Territorial evolution of Mexico

Mexico has experienced many changes in territorial organization during its history as an independent state. The territorial boundaries of Mexico were affected by presidential and imperial decrees. One such decree was the Law of Bases for the Convocation of the Constituent Congress to the Constitutive Act of the Mexican Federation, which determined the national land area as the result of integration of the jurisdictions that corresponded to New Spain, the Captaincy General of Yucatán, the Captaincy General of Guatemala and the autonomous Kingdoms of East and West. The decree resulted in the independence from Spain.


Subdivision by intendancies

During the period of the Independence of Mexico, part of the territorial organization of New Spain was integrated into the new nation of the Mexican Empire. Added to this were the Captaincy General of Yucatán and the Captaincy General of Guatemala (whose annexation was a strategy to counteract the Spanish crown). This yielded Mexico's largest land area as an independent nation.

Subdivision by state and territory

During the structuring of the Republic, territorial and legal changes reaffirmed the Catholic Church's status as the only religion for Mexicans. The new nation developed a popular and representative federal republic that recognized the sovereignty of the States constituting the federal union.

Subdivision by department

The liberal government of Antonio López de Santa Anna, influenced by conservatives, ratified the Seven Laws by presidential decree, establishing a new territorial court and replacing the federal states by departments whose governors and legislators would be selected by the President. This break from federalism brought Mexico its most turbulent and unstable era.

During the Second Mexican Empire, Emperor Maximilian I of Mexico made a new division of national territory.

Territorial divisions throughout Mexican history were generally linked to political change and programs aimed at improving the administrative, country's economic and social development. On 3 March 1865, one of the most important decrees of the government of Maximilian, the first division of the territory of the new Empire, was issued and published in the Journal of the Empire on 13 March. The reorganization was accomplished by Manuel Orozco y Berra (1816–1881), and was made according to the following rules:

  • The total land area of the country will be divided into at least fifty departments.
  • Whenever possible, natural features will be used for boundaries.
  • The surface area of each department will take into account the terrain, weather, and all elements of production, so that (eventually) the departments will hold an equal number of inhabitants.

This division was of great importance, because geographical features and projected development were taken into account for the delimitation of the jurisdictions.[1]

The territorial division of the Second Mexican Empire was used for a short period because the Empire was overthrown in early 1867 with the execution of Maximilian I. The Federal Republic, and its former divisions, were restored in that year.


Several of the former borders of the states and territories in northern Mexico remain unclear. The northern border of Sonora, for example, is described in various ways, either as the Gila River or the Colorado River. The list of acts is not affected by this confusion, but the associated maps contain the following uncertainties and omissions:

Some of the borders of states in the north, and in northeast Texas, before independence and the Mexican Cession

  • The territorial extent of the Santa Fe de Nuevo México Territory
  • The exact date that the division between Durango and Chihuahua stopped being a straight line
  • Several minor adjustments to the border with the United States, including the Chamizal dispute are not specified
  • The Republic of Baja California and Republic of Sonora - proclaimed by the American William Walker in 1854, were never more than a declaration and are not shown on maps.
  • The following maps do not show the separation of Zacatecas (in 1835) and Tabasco (in 1841-1842), which never became independent republics and were never proclaimed as such.
  • The maps do not show the claim of Mexico on part of the former British Honduras, today called Belize.

Territorial evolution of Mexico


From Independence to the Constitution of 1824
Map Date Description
Mexico 1821
September 27, 1821
The territorial organization of the First Mexican Empire was the largest extension of Mexico as an independent country: 4,925,283 km2.

The 24 intendencies of the Empire were:

  • Querétaro
  • Puebla
  • Guadalajara
  • Oaxaca
  • Mérida de Yucatán
  • Valladolid
  • Veracruz
  • Guatemala
  • El Salvador
  • Honduras
  • Nicaragua
  • Costa Rica
Mapa Mexico 1823
May 21, 1823
Territorial organization under the interim government of Mexico after the establishment of the Republic on May 21, 1823, and before the decree of the Constitutive Act of the Mexican Federation on January 31, 1824 - the period between the end of the First Mexican Empire and the creation of the Federal Republic of the United Mexican States.

After the end of the empire, the Central American provinces decided not to be part of Mexico. Chiapas (part of Guatemala) was not yet part of Mexico, while the region of Soconusco proclaimed its independence of Mexico on 24 July 1824, and was formally annexed by the Federal Republic of Central America on August 18, 1824.


From the Constitution of 1824 to the Constitution of 1857
Map Date Description
Mexico 1824
October 4, 1824
The Constitution of 1824 officially established the United Mexican States.

The constitution organized the country in 19 states and four territories. The order of the states is determined by the date of accession to the federation, listed in the order in which the constitutional congress of the state was instated. The 19 founding states were:[2]

Order Name Date of Admission to Federation Installation date of the Congress
1823-12-20 02-03-1824
1823-12-20 25-03-1825
1823-12-21 01-07-1823
1823-12-21 19-03-1824
1823-12-22 06-04-1824
San Luis Potosí
1823-12-22 21-04-1824
1823-12-22 09-05-1824
1823-12-23 20-08-1823
1823-12-23 14-09-1823
1823-12-23 19-10-1823
1823-12-23 17-02-1824
Sonora y Sinaloa
1824-01-10 12-09-1824
1824-02-07 03-05-1824
1824-02-07 07-05-1824
Nuevo León
1824-05-07 01-08-1824
Coahuila y Texas
1824-05-07 15-08-1824
1824-05-22 08-09-1824
1824-07-06 08-09-1824
1824-09-14 05-01-1825

The four federal territories were:

Alta California
Baja California Territory
Colima Territory
Nuevo México Territory
Mapa de Mexico 1824 2
November 18, 1824
The Federal District was established around the City of Mexico, separating it from the State of Mexico. The Federal District was originally a perfect circle with an area of 220 square kilometres (85 sq mi), centered on the Zócalo (Constitution Square). In 1854, Antonio López de Santa Anna enlarged the Federal District's area to 1,700 square kilometres (660 sq mi), before it was reduced to the current 1,479 square kilometres (571 sq mi) between 1898 and 1902, during the rule of Porfirio Díaz. This map shows only the current area of the Federal District.
Mapa de Mexico 1824 3
November 24, 1824
The Tlaxcala Territory was created out of part of the state of Puebla.
Mapa Mexico 1830
October 14, 1830
Sonora and Sinaloa became separate states.

Created as a state:

Order Name Date of Admission
Mapa de Mexico 1835 1
May 23, 1835[4]
The Aguascalientes Territory was created out of part of the state of Zacatecas.
Mapa Mexico 1836
April 21, 1836
The region of Texas of the state of Coahuila y Texas declared its independence. The rest of the state was named Coahuila. The Treaties of Velasco ended the Texas Revolution on May 14, 1836 with the creation of the independent Republic of Texas.
Mapa Mexico 1837
Texas published a map claiming the Rio Grande as its border with Mexico and not the Nueces River, the border since the Spanish colonial era.[5] The Mexican Congress rejected the Treaties of Velasco signed by Antonio López de Santa Anna, arguing that Santa Anna had no authority to grant independence to Texas.
Mapa Mexico 1840 1
January 17, 1840
The states of Coahuila, Nuevo León and Tamaulipas declared their independence from Mexico as the Republic of the Rio Grande, which also took the eastern part of the state of Chihuahua. However, the border with Texas was never determined: the Republic claimed the Nueces River as its northern border, while Texas continued to claim the Rio Grande as its southern border.
Mapa de Mexico 1840 2
November 6, 1840
The Republic of the Rio Grande returned to Mexico after a brief and unsuccessful war for independence. Coahuila kept the part of Chihuahua taken by the Republic.
Mapa de Mexico 1841
October 1, 1841
On February 12, 1840, Yucatán sent a report to the central government demanding the restoration of federalism as a form of government to combat poverty in the country. The act demanded the re-establishment of the Mexican Constitution of 1824. On October 1, 1841, the local Chamber of Deputies enacted the Declaration of Independence of the Yucatán Peninsula, thus establishing the second Republic of Yucatán.
Mapa Mexico 1842
September 11, 1842
The region of Soconusco was annexed by Mexico as part of the state of Chiapas, following the dissolution of the Federal Republic of Central America.
Mapa Mexico 1845
December 29, 1845
The U.S. annexed the Republic of Texas and admitted it to the Union as the State of Texas. Mexico did not accept the annexation, while also continuing to claim the Nueces River as its border with Texas. The dispute ultimately provoked the Mexican–American War, which began on April 25, 1846.
Mapa Mexico 1848 1
February 2, 1848
The Treaty of Guadalupe Hidalgo officially ended the Mexican–American War, forcing large territorial concessions by Mexico. All claims over Texas were abandoned, while the Rio Grande was established as the permanent border between the countries, thus giving portions of the states of Chihuahua, Coahuila and Tamaulipas to the United States.

In addition, the U.S. received what is now known as the Mexican Cession, equivalent to the territories of Alta California and Santa Fe de Nuevo México. Including Texas, Mexico ceded an area of approximately 2,500,000 square kilometres (970,000 sq mi) – by its terms, around 55% of its former national territory.[6]

Mapa Mexico 1848 2
August 17, 1848
On August 22, 1846, interim president José Mariano Salas re-enacted the Constitution of 1824. Two years later, during the government of José Joaquín de Herrera, Yucatán reunited with Mexico.

A decisive factor for the reunion was the Caste War, which forced Yucatán to seek outside help.

Mapa Mexico 1853 1
December 30, 1853
On December 30, 1853, Antonio López de Santa Anna signed a treaty with James Gadsden, the U.S. Ambassador to Mexico, which involved the sale of an area of 76,845 square kilometres (29,670 sq mi) from the states of Sonora and Chihuahua to the United States for $10 million. This treaty became known as the Gadsden Purchase (and as Venta de la Mesilla in Mexico).

The treaty was ratified by the United States Senate on April 25, 1854 and signed by U.S. President Franklin Pierce. Final approval by the Mexican Congress took place on June 8, 1854.

Mapa de Mexico 1854
April 25, 1854
After the United States Senate approved the Gadsden Purchase on April 25, 1854, the sale became official.

Mexican people angered by the sale proclaimed the Plan of Ayutla, which finally ended the political career of Santa Anna.


From the Constitution of 1857 to the Constitution of 1917
Map Date Description
Mapa de Mexico en 1857
February 5, 1857
The Federal Constitution of the United Mexican States of 1857 approved the reorganization of the national territory. Nuevo León merged with Coahuila, adopting the name of the latter. Also confirmed were the creation of a new state and the admission of 3 of the 4 territories as free states of the federation.

Created as a state::

Order Name Date of Admission Installation date of the Congress
27-10-1849[7] 30-01-1850

Admitted as states:

Order Name Date of Admission Installation date of the Congress
09-12-1856[8] 01-06-1857
09-12-1856[9][10] 19-07-1857
Mapa Mexico 1858
May 3, 1858
The Campeche District was separated from the state of Yucatán, creating the Campeche Territory.
Mapa Mexico 1863
April 29, 1863
Admitted as a state:
Order Name Date of Admission Installation date of the Congress
Mapa de Mexico 1864
February 26, 1864
President Benito Juárez, at Saltillo, decreed the separation of Coahuila and Nuevo León as 2 free and sovereign states, as they were before 1857.
Mapa de Mexico 1865
March 3, 1865
On October 3, 1863, conservative Mexicans and the Catholic Church,[13] which were unhappy with the government of Benito Juárez and the constitution of 1857, offered the crown of Mexico to the Austrian archduke Maximilian von Habsburg. On March 3, 1865, he decreed the first division of the territory of the new Empire, which was published in the Journal of the Empire on March 13 of that year.
Mapa de Mexico 1864
July 15, 1867
Emperor Maximilian was executed.

On 15 July 1867, President Benito Juárez entered the city of Mexico, formally restoring the Federal Republic.

Mapa de Mexico 1869 1
January 16, 1869
By decree of President Benito Juárez and with unanimous approval of Congress with parts of the State of Mexico

Created as a state:

Order Name Date of Admission Installation date of the Congress
16-01-1869[14] 16-05-1869
Mapa de Mexico 1869 2
April 17, 1869
By decree of President Benito Juárez and with unanimous approval of Congress with parts of the State of Mexico

Created as a state:

Order Name Date of Admission Installation date of the Congress
Mapa de Mexico 1884
December 12, 1884
By decree of President Manuel González, the Tepic Territory was created, separating from the state of Jalisco.
Mapa de Mexico 1902
November 24, 1902
Britain and Mexico, in 1893, agreed on the Rio Hondo as the border between Mexico and British Honduras, which was finalized in 1897. By decree of President Porfirio Díaz, the Quintana Roo Territory was created, separating from the state of Yucatán.
Mapa de Mexico 1917
January 26, 1917
The Tepic Territory was admitted as the state of:
Order Name Date of Admission Installation date of the Congress


From the Constitution of 1917 to present
Map Date Description
Mapa de Mexico 1917
February 5, 1917
As a result of the Mexican Revolution, the Political Constitution of the United Mexican States of 1917 was enacted. The constitution ratified many social demands dating to the beginning of the Revolution, and was the first constitution in history to include so-called social rights. The admission of the state of Nayarit to the federation was ratified.
Mapa de Mexico 1930
December 30, 1930[17]
On December 30, 1930, Congress and local legislatures approved the amendments to the Constitution which created the North Territory of Baja California and the South Territory of Baja California, divided at the 28th parallel. They were published in the Official Gazette of the Federation on February 7, 1931.
Mapa de Mexico 1931 1
January 28, 1931
Victor Emmanuel III of Italy handed down his verdict in favor of France for the possession of Clipperton Island, also known as Isla de la Pasion, by which Mexico lost the sovereignty of that atoll.
Mapa Mexico 1931 2
December 14, 1931
President Pascual Ortiz Rubio declared the annexation of the Quintana Roo Territory to the states of Yucatán and Campeche, giving as an excuse that the territory, not being economically self-sufficient, was a huge outflow for the federation.
Mapa de Mexico 1931 1
January 11, 1935[18]
President Lázaro Cárdenas issued a decree published in the Official Journal on January 16, 1935, by which the Federal Territory of Quintana Roo was reconstituted.
Mapa de Mexico 1952
January 16, 1952
President Miguel Alemán Valdés announced on September 1, 1951 that the North Territory of Baja California, due to its population and its economic ability to survive, satisfied the conditions required by the Constitution to be admitted as a free and sovereign state .

The North Territory of Baja California was admitted as the state of

Order Name Date of Admission
Baja California
Mapa Mexico 1974
October 8, 1974[20]
President Luis Echeverría Álvarez sent to the Congress of Mexico a bill for the Quintana Roo Territory and South Territory of Baja California to be elevated to the category of states.

Following the approval of state legislatures, on October 8, 1974, the decree, giving Mexico its current configuration, was published in the Official Gazette of the Federation.

The South Territory of Baja California and the Quintana Roo Territory were admitted as the states of:

Order Name Date of Admission Installation date of the Congress
Quintana Roo
08-10-1974 25-11-1974[21]
Baja California Sur
08-10-1974 25-03-1975[22]
Mexico–United States International Boundary and Water Commission
International Boundary and Water Commission

The Banco Convention of 1905 resulted in many exchanges of bancos (land surrounded by bends in the river that became segregated from either country by a cutoff, often due to rapid accretion or avulsion of the alluvial channel) between the two nations, most often in the Lower Rio Grande Valley. Under the treaty, the following transfers involving Texas occurred from 1910 – 1976:[23]

Year # Bancos Acres to USA Acres to Mexico Year # Bancos Acres to USA Acres to Mexico
1910 57 5357.1 3101.2 1942 1 63.3 0
1912 31 1094.4 2342.8 1943 4 482.9 100.5
1928 42 3089.9 1407.8 1944 14 253.7 166.2
1930 31 4685.7 984.3 1945 16 240.9 333.5
1931 4 158.4 328.7 1946 1 185.8 0
1932 2 159.7 0 1949 2 190.2 182.0
1933 1 0 122.1 1956 1 508.3 0
1934 1 278.1 0 1968 1 0 154.6
1939 1 240.2 0 1970 21 449.8 1881.8
1940 2 0 209.5 1976 6 49.2 0
1941 6 224.5 246.9 Total 245 17,712 acres (71.68 km2) 11,662 acres (47.19 km2)
1910 - November 24, 2009

In 1927 under the same 1905 Convention, the U.S. acquired two bancos from Mexico at the Colorado River border with Arizona. Farmers Banco, covering 583.4 acres (2.361 km2), a part of the Cocopah Indian Reservation at 32°37′27″N 114°46′45″W / 32.62417°N 114.77917°W, was ceded to the U.S. with controversy.[24] Fain Banco (259 acres (1.05 km2)) at 32°31′32″N 114°47′28″W / 32.52556°N 114.79111°W also became U.S. soil.

The Rio Grande Rectification Treaty of 1933 straightened and stabilized the 155 miles (249 km) of river boundary through the highly developed El Paso-Juárez Valley. Numerous parcels of land (174) were transferred between the two countries during the construction period, 1935 – 1938. At the end, each nation had ceded an equal area of land (2,560.5 acres (10.362 km2)) to the other.

The Chamizal Treaty of 1963, which ended a hundred-year dispute between the two countries near El Paso, Texas, transferred 630 acres (2.5 km2) from the U.S. to Mexico in 1967. In return, Mexico transferred 264 acres (1.07 km2) to the U.S.

The Boundary Treaty of 1970 transferred 823 acres (3.33 km2) of Mexican territory to the U.S., in areas near Presidio and Hidalgo, Texas, to build flood control channels. In exchange, the U.S. ceded 2,177 acres (8.81 km2) to Mexico, including five parcels near Presidio, the Horcon Tract containing the little town of Rio Rico, Texas, and Beaver Island near Roma, Texas. The last of these transfers occurred in 1977.

On November 24, 2009, the U.S. ceded 6 islands in the Rio Grande to Mexico, totaling 107.81 acres (0.4363 km2). At the same time, Mexico ceded 3 islands and 2 cuts to the U.S., totaling 63.53 acres (0.2571 km2). This transfer, which had been pending for 20 years, was the first application of Article III of the 1970 Boundary Treaty.

The Centralist Republic

The Seven Constitutional Laws

Political divisions of Mexico 1836-1845 (location map scheme)
The Centralist Republic with the separatist movements generated by the dissolution of the Federal Republic.
  Territory proclaimed its independency
  Territory claimed by the Republic of Texas
  Territory claimed by the Republic of the Rio Grande

By the law of October 3, 1835, the centralist system was introduced in the country. The entities that formed the Republic lost their freedom, independence and sovereignty, becoming entirely subordinate to the central government.

The Seven Constitutional Laws were enacted on December 30, 1836. The sixth discussed the territorial configuration in its first and second articles. Shortly thereafter, the Eighth Organic Base—a separate statute from the Seven Laws—was enacted. The first article stipulated that the country would be composed of many departments, corresponding to the previously existing states, except that:

  1. Coahuila and Texas were separated into two different departments
  2. Colima Territory would be integrated into the Michoacán Department
  3. Tlaxcala Territory would be integrated into the Mexico Department
  4. The Federal District was eliminated

Accordingly, the new territorial division was composed of 24 departments. That initial territorial composition was regarded as final until 30 June 1838, by law of that date.

This period created a great political instability that began in regional problems and conflicts between the central entity and the states of the country. Rebellions were raised in several places, among which the following were particularly distinguished:

  • Zacatecas was the first state to declare itself against centralism in the so-called 1835 Revolt in Zacatecas, which was quickly extinguished. As punishment for this rebellion, part of the territory of Zacatecas was split off and turned into the Aguascalientes Territory
  • The Texas region of the state of Coahuila and Texas declared its independence from Mexico on October 2, 1835, forming the Republic of Texas
  • Coahuila, Nuevo León, and Tamaulipas declared themselves independent of Mexico on January 17, 1840, as the Republic of the Rio Grande. The Republic was never truly independent, since the rebels were quickly overthrown. The Republic was dissolved on 6 November 1840
  • Yucatán, which had joined to the federation under the condition of a Federated Republic, declared its independence in 1840 (officially on October 1, 1841). This historic event resulted in the birth of the second Republic of Yucatán, which returned permanently to the nation in 1848
  • Tabasco, due to conflicts with the new centralized system, declared independence from Mexico on 13 February 1841, returning to the nation on December 2, 1842
Mapa Mexico (1836-1846) Republica Centralista
Map of Mexico between 1836 and 1846, from the secession of Texas, Rio grande, and Yucatán to the Mexican–American War of 1846.

On August 22, 1846, due to the war with the United States, the Federal Constitution of the United Mexican States of 1824 was restored. There remained the separation of Yucatán, but 2 years later Yucatán definitively rejoined Mexico.

The Basis for Administration of the Republic

Mapa Mexico (1853 -1856)
Map of Mexico between 1853 and 1856 during the Basis for the Administration of the Republic until the promulgation of the Constitution of 1857.

A change in the governance of the country was determined by the Decree of 22 April 1853, which from that moment recognized the Basis for the Administration of the Republic as the fundamental law for the reorganization of government.

In this precept, in the first and second articles, the Section of Internal Governance, the independence and sovereignty of states were abolished, although the name "states" was retained.

In the third article districts, cities, or towns that had been separated from the states and divisions to which they belonged were returned to their original conditions. This excluded Aguascalientes, which continued to be considered a district of Zacatecas.

In a statement by the Ministry of War, on September 21, 1853, it was decided that states would instead be called "departments".

Changes in the territorial division, according to the code above, were established according to several decrees:

  1. May 29, 1853, establishing the Tehuantepec Territory, its capital city at Minatitlan
  2. October 16, 1853, establishing the Isla del Carmen Territory
  3. December 1, 1853, establishing the Sierra Gorda Territory, its capital city at San Luis de la Paz
  4. December 1, 1853, adding Tuxpan District to the Veracruz Department
  5. December 10, 1853, redesignating Aguascalientes District as Aguascalientes Department
  6. February 16, 1854 creating, despite the centralist system, a kind of Federal District
  7. July 20, 1854, approving the Treaty of Mesilla, which amended the border with the United States of America through the loss of territory of Chihuahua and Sonora.

Plan of Ayutla

The Plan of Ayutla was a political statement proclaimed on March 1, 1854 in Ayutla, Guerrero, and was intended to end the presidency of Antonio López de Santa Anna.

The plan was revised in Acapulco on 11 March 1854, by changing its second article to respect in principle the territorial division and to create a representative from each department and territory.

The Provisional Organic Statute (known as Lafragua Code) was promulgated on May 15, 1856. It provided the legal basis for governing the country in the period between the Plan of Ayutla and Federal Constitution of the United Mexican States of 1857. That document left open a later choice for federalism or centralism, but encouraged federalism because it called the entities that formed the Republic States. Thus, in its 2nd article, it retained the previous territorial division, and determined the existence of 22 states, the District of the capital, and 6 territories.

The Constitution of 1857 was drafted during the presidency of Ignacio Comonfort, who was sworn in on February 5, 1857. The Constitution contained the essence of the 1824 document (i.e. the federal character of the state and the democratic system of representative and republican government), but established freedom of religion and ended the domain of the Catholic Church as the sole and official religion of the country. It set out, in Article 43, the parties making up the federation - 24 states, 1 federal territory, and the Federal District known as the Valley of Mexico (today Mexico City). The territories of Sierra Gorda, Tehuantepec and Isla del Carmen, and Nuevo León as an independent state, disappeared (Nuevo León was later restored).


  1. ^ "Commons, Aurea, La división territorial del Segundo Imperio Mexicano, 1865" (in Spanish).
  2. ^ "La diputación provincial y el federalismo mexicano" (in Spanish).
  3. ^ "500 años de México en documentos" (in Spanish).
  4. ^ "Enciclopedia de los Municipios de México" (in Spanish). Archived from the original on 2011-06-16.
  5. ^ "Global Security.org".
  6. ^ "Treaty of Guadalupe Hidalgo (1848)".
  7. ^ "Portal Estado de Guerrero" (in Spanish). Archived from the original on 2007-10-17.
  8. ^ "Portal Gobierno del Estado de Tlaxcala" (in Spanish). Archived from the original on 2009-12-27.
  9. ^ "Portal Ciudadano de Baja California" (in Spanish).
  10. ^ "El Comentario" (in Spanish). Archived from the original on 2010-08-10.
  11. ^ "Gobierno del Estado de Yucatán" (in Spanish). Archived from the original on 2010-04-11.
  12. ^ "SEP" (in Spanish). Archived from the original on 2011-10-26.
  13. ^ Martin Quirarte. "Visión panorámica de la historia de México". Librería Porrúa Hnos y Cia, S. A. 27a. edición 1995. México, D. F. Pág. 170-171.
  14. ^ "Mexico 2010" (in Spanish).
  15. ^ "Congreso de Morelos" (in Spanish).
  16. ^ "Portal del Gobierno del Estado de Tlaxcala" (in Spanish). Archived from the original on 2010-02-18.
  17. ^ "Historia de Baja California" (in Spanish).
  18. ^ "Oficialía Mayor del Estado de Quintana Roo" (in Spanish). Archived from the original on 2011-07-22.
  19. ^ "Transformación Política de Territorio Norte de la Baja California a Estado 29" (in Spanish).
  20. ^ "SEP" (in Spanish). Archived from the original on 2010-08-10.
  21. ^ "Poder Legislativo del Estado de Quintana Roo" (PDF) (in Spanish). Archived from the original (PDF) on 2011-10-12.
  22. ^ "Constitución Baja California Sur, Articulo 12 transitorio" (in Spanish).
  23. ^ Mueller, Jerry E. (1975). Restless River, International Law and the Behavior of the Rio Grande. Texas Western Press. p. 64. ISBN 9780874040500.
  24. ^ Decisions of the Department of the Interior in cases relating to the public lands: 1927-1954. United States. Department of the Interior. Washington. For sale by the Supt. of Docs., U.S. Govt. Print. Off. pp. 25, 337. Retrieved 2013-07-25.
Administrative divisions of Mexico

The United Mexican States (Spanish: Estados Unidos Mexicanos) is a federal republic composed of 31 states and the capital, Mexico City, an autonomous entity.

According to the Constitution of 1917, the states of the federation are free and sovereign in all matters concerning their internal affairs. Each state has its own congress and constitution.

Coahuila y Tejas

Coahuila y Tejas (Coahuila and Texas) was one of the constituent states of the newly established United Mexican States under its 1824 Constitution.It had two capitals: first Saltillo (1822–1825) for petition of Miguel Ramos Arizpe, that changing the capital for dispute of political groups, but Monclova recovered primacy because it was the colonial capital since 1689; this action provoked a struggle between the residents of Saltillo and Monclova in 1838–1840, but the political actions of Santa Anna convinced the monclovitas to accept the final change of political powers to Saltillo. In the case of Tejas its territory was organized for administrative purposes, with the state being divided into three districts: Béxar, comprising the area covered by Texas; Monclova, comprising northern Coahuila; and Río Grande Saltillo, comprising southern Coahuila.

The state remained in existence until the adoption of the 1835 "Constitutional Bases", whereby the federal republic was converted into a unitary one, and the nation's states (estados) were turned into departments (departamentos). The State of Coahuila and Texas was split in two and became the Department of Coahuila and the Department of Texas.

Both Coahuila and Texas seceded from Mexico because of Antonio López de Santa Anna's attempts to centralize the government. Texas eventually became the independent Republic of Texas, which in 1845 became a state of the United States of America. Coahuila joined with Nuevo León and Tamaulipas, to form the short-lived Republic of the Rio Grande.

First Mexican Empire

The Mexican Empire (Spanish: Imperio Mexicano, pronounced [ĩmˈpeɾjo mexiˈcano]) was a short-lived monarchy, and the first independent post-colonial imperial state in Mexico. It was the only former colony of the Spanish Empire to establish a monarchy after independence. Together with the Brazilian Empire and the two Haitian Empires, it was one of four European-style empires in the Americas; it lasted two years before transitioning into a federal republic.

It existed from the signing of the Treaty of Córdoba and the declaration of Independence of the Mexican Empire in September 1821 until the emperor's abdication in March 1823 when the Provisional Government took power and the First Mexican Republic was proclaimed in 1824. The first monarch of the state was Agustín de Iturbide, reigning as Agustín I of Mexico.

Flag of Yucatán

The Flag of Yucatán was the flag used by the former Republic of Yucatán, when in the middle of 19th century it was proclaimed in the territory of the Yucatán Peninsula. The republic comprised the present Mexican states of Yucatán, Campeche and Quintana Roo.

List of Mexican states by date of statehood

This is a list of Mexican States by date of statehood, that is, the date when each Mexican State was accepted by Congress of the Union as a free and sovereign state of the Mexican Union.

The effective independence of Mexico reached on September 27, 1821, does not meant the independence of the states, because Mexico was the only Latin American country which became independent from Spain as a monarchy. After the fall of the Mexican Empire, the Federal Republic was established on July 12, 1823.Although 18 of the 19 founder states can be considered official members of the federation since the enactment of the Constitutive Act of the Mexican Federation on January 31, 1824; eleven of them were ratified as states before the enactment and some of the others were included as three states (the internal States of North, Western and Eastern).6 7 Tamaulipas, Tabasco and Chiapas were ratified after the enactment of the act.8All the later admission dates were set by law or decree of congress, except for Chiapas, whose admission was determined by its own people in a referendum.This list does not account the secession of several states during the establishment of the Centralist Republic and the territorial changes made during the civil and foreign wars.

List of states of Mexico

The states of Mexico are first-level administrative territorial entities of the country of Mexico, which officially is named United Mexican States. There are 31 states and one federal entity in Mexico. Mexico City is a federal entity with a level of autonomy comparable to that of a state, but is not a state itself.The states are further divided into municipalities.

Mexican Cession

The Mexican Cession is the region in the modern-day southwestern United States that Mexico ceded to the U.S. in the Treaty of Guadalupe Hidalgo in 1848 after the Mexican–American War. This region had not been part of the areas east of the Rio Grande which had been claimed by the Republic of Texas, though the Texas annexation resolution two years earlier had not specified the southern and western boundary of the new State of Texas. The Mexican Cession (529,000 sq. miles) was the third largest acquisition of territory in US history. The largest was the Louisiana Purchase, with some 827,000 sq. miles (including land from fifteen present U.S. states and two Canadian provinces), followed by the acquisition of Alaska (about 586,000 sq. miles).

Most of the area had been the Mexican territory of Alta California, while a southeastern strip on the Rio Grande had been part of Santa Fe de Nuevo Mexico, most of whose area and population were east of the Rio Grande on land that had been claimed by the Republic of Texas since 1835, but never controlled or even approached aside from the Texan Santa Fe Expedition. Mexico controlled the territory later known as the Mexican Cession, with considerable local autonomy punctuated by several revolts and few troops sent from central Mexico, in the period from 1821–22 after independence from Spain up through 1846 when U.S. military forces seized control of California and New Mexico on the outbreak of the Mexican–American War. The northern boundary of the 42nd parallel north was set by the Adams–Onís Treaty signed by the United States and Spain in 1821 and ratified by Mexico in 1831 in the Treaty of Limits (Mexico-United States). The eastern boundary of the Mexican Cession was the Texas claim at the Rio Grande and extending north from the headwaters of the Rio Grande, not corresponding to Mexican territorial boundaries. The southern boundary was set by the Treaty of Guadalupe Hidalgo, which followed the Mexican boundaries between Alta California (to the north) and Baja California and Sonora (to the south). The United States paid Mexico $15 million for the land which became known as the Mexican Cession.


Mexico (Spanish: México [ˈmexiko] (listen); Nahuatl languages: Mēxihco), officially the United Mexican States (Spanish: Estados Unidos Mexicanos [esˈtaðos uˈniðoz mexiˈkanos] (listen)), is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Covering almost 2,000,000 square kilometres (770,000 sq mi), the nation is the fifth largest country in the Americas by total area and the 13th largest independent state in the world. With an estimated population of over 120 million people, the country is the tenth most populous state and the most populous Spanish-speaking state in the world, while being the second most populous nation in Latin America after Brazil. Mexico is a federation comprising 31 states and Mexico City, a special federal entity that is also the capital city and its most populous city. Other metropolises in the state include Guadalajara, Monterrey, Puebla, Toluca, Tijuana and León.

Pre-Columbian Mexico dates to about 8000 BC and is identified as one of five cradles of civilization and was home to many advanced Mesoamerican civilizations such as the Olmec, Toltec, Teotihuacan, Zapotec, Maya, and Aztec before first contact with Europeans. In 1521, the Spanish Empire conquered and colonized the territory from its politically powerful base in Mexico-Tenochtitlan (part of Mexico City), which was administered as the viceroyalty of New Spain. Three centuries later, the territory became a nation state following its recognition in 1821 after the Mexican War of Independence. The post-independence period was tumultuous, characterized by economic inequality and many contrasting political changes. The Mexican–American War (1846–1848) led to a territorial cession of the extant northern territories to the United States. The Pastry War, the Franco-Mexican War, a civil war, two empires, and the Porfiriato occurred in the 19th century. The Porfiriato ended with the Mexican Revolution in 1910, which culminated in the promulgation of the 1917 Constitution and the emergence of an authoritarian one-party state, once widely described as the "perfect dictatorship," that ruled for much of the 20th Century until electoral reforms and opposition victories led to Mexico's democratic transition in the 1990s.Mexico has the 15th largest nominal GDP and the 11th largest by purchasing power parity. The Mexican economy is strongly linked to those of its 1994 North American Free Trade Agreement (NAFTA) partners, especially the United States. In 1994, Mexico became the first Latin American member of the Organisation for Economic Co-operation and Development (OECD). It is classified as an upper-middle income country by the World Bank and a newly industrialized country by several analysts. The country is considered both a regional power and a middle power, and is often identified as an emerging global power. Due to its rich culture and history, Mexico ranks first in the Americas and seventh in the world for number of UNESCO World Heritage Sites. Mexico is an ecologically megadiverse country, ranking fourth in the world for its biodiversity. Mexico receives a huge number of tourists every year: in 2018, it was the sixth most-visited country in the world, with 39 million international arrivals. Mexico is a member of the United Nations (UN), the World Trade Organization (WTO), the G8+5, the G20, the Uniting for Consensus group of the UN, and the Pacific Alliance trade bloc.

Mexico–United States relations

Mexico–United States relations refers to the foreign relations between the bordering countries of Mexico and the United States. The two countries share a maritime and land border in North America. Several treaties have been concluded between the two nations bilaterally, such as the Gadsden Purchase, and multilaterally, such as the North American Free Trade Agreement. Both are members of various international organizations, including the Organization of American States and the United Nations.

Since the late nineteenth century during the regime of President Porfirio Díaz (1876–1911), the two countries have had close diplomatic and economic ties. During Díaz's long presidency, Mexico was opened to foreign investment and U.S. entrepreneurs invested in ranching and agricultural enterprises and mining. The U.S. played an important role in the course of the Mexican Revolution (1910–20) with direct actions of the U.S. government in supporting or repudiating support of revolutionary factions.

The long border between the two countries means that peace and security in that region is important to the U.S.'s national security and international trade. The U.S. is Mexico's biggest trading partner and Mexico is the U.S.'s third largest trading partners. In 2010, Mexico's exports totaled US$309.6 billion, and almost three quarters of those purchases were made by the United States. They are also closely connected demographically, with over one million U.S. citizens living in Mexico and Mexico being the largest source of immigrants to the United States. Illegal immigration and illegal trade in drugs and in fire arms have been causes of differences between the two governments, but also of cooperation.

While condemning the terrorist attacks of 9/11 and providing considerable relief aid to the U.S. after Hurricane Katrina, the Mexican government, pursuing neutrality in international affairs, opted not to actively join the controversial War on Terror and the even more controversial Iraq War, instead being the first nation in history to formally and voluntarily leave the Inter-American Treaty of Reciprocal Assistance in 2002, though Mexico later joined the U.S. in supporting military intervention in the Libyan Civil War.According to a 2010 Gallup poll, 4.4% of surveyed Mexicans, roughly 6.2 million people, say that they would move permanently to the United States if given the chance, and according to the 2012 U.S. Global Leadership Report, 37% of Mexicans approve of U.S. leadership, with 27% disapproving and 36% uncertain. As of 2013, Mexican students form the 9th largest group of international students studying in the United States, representing 1.7% of all foreigners pursuing higher education in the U.S. The election of Donald Trump, who had provoked the ire of the Mexican government through threats against companies who invest in Mexico instead of the U.S, and his claims that he would construct a border wall and force Mexico to fund its construction, has raised questions over the future of the relationship between the United States and Mexico.

A 2017 survey conducted by the Pew Research Center showed 65% of Mexicans had a negative view of the US, with only 30% having a positive view. The same study also showed only 5% of Mexicans had confidence in the current US leader, President Donald Trump, with 93% having no confidence in the current US president.

New Navarre

New Navarre (Spanish: Nueva Navarra, Basque: Nafarroa Berria) was a province in the Provincias Internas, one of the frontier provinces of the Viceroyalty of New Spain. Brigadier Pedro de Rivera, who visited the northern presidios from 1724 to 1728, suggested to the viceroy Juan de Acuña, Marquis of Casafuerte, the political and administrative reorganization of the northwest provinces. The viceroy supported the idea, and it was approved by Philip V of Spain in 1732, and executed the following year with the appointment of the first governor, Manuel Bernal de Huidobro, at that time mayor of Sinaloa. In the branches of government, finance and war, the governor was directly subject to the viceroy, while the field of justice was under the jurisdiction of the Royal Audience of Guadalajara (Real Audiencia of Guadalajara) of the Viceroyalty of New Spain. By 1806, the province was generally recognized as Sonora or Nueva Navarra, with the capital in Arispe, and including the area comprising Sinaloa (de Iriarte, 1806). After Independence Sonora y Sinaloa became one of the constituent states of the Mexican Republic. The Sonoran Desert ecoregion covers much of the state.

In the early years of European migration to Nueva Navarra, the Basques became a significant proportion of the population. The Basque immigrants reached 6% of total migrants in the first 15 years of colonization, the same percentage as those from the Castile or Extremadura, most populated regions. More specific data shows ratios between 8% and 16% of Basques in the nuclei urban settlements of those first decades, indicating a trend which would persist in the future: the Basque-Navarre preference for urban settlement (Boyde-Bowman, 1964).

Nueva Extremadura

Nueva Extremadura means "New Extremadura" in Spanish and comes from Extremadura, Spain.

Nueva Extremadura could refer to

a region in the north of New Spain, roughly placed on the border between present-day Coahuila and Texas.

the name originally given to Chile by Pedro de Valdivia. Its capital was then known as Santiago de Nueva Extremadura.

Provincias Internas

The Provincias Internas, also known as the Comandancia y Capitanía General de las Provincias Internas (Commandancy and Captaincy General of the Internal Provinces), was an administrative district of the Spanish Empire created in 1776 to provide more autonomy for the frontier provinces of the Viceroyalty of New Spain, present-day northern Mexico and the Southwestern United States. The goal of its creation was to establish a unified government in political, military and fiscal affairs. Nevertheless, the Commandancy General experienced significant changes in its administration because of experimentation to find the best government for the frontier region as well as bureaucratic in-fighting. Its creation was part of the Bourbon Reforms and was part of an effort to invigorate economic and population growth in the region to stave off encroachment on the region by foreign powers. During its existence, the Commandancy General encompassed the Provinces of Sonora y Sinaloa, Nueva Vizcaya, Las Californias, Nuevo México, Nuevo Santander, Nuevo Reyno de León, Coahuila (formerly Nueva Extremadura) and Texas.

Real Audiencia of Mexico

The Real Audiencia of Mexico (Spanish: Real Audiencia de México) or high court was the highest tribunal of the Spanish crown in the Kingdom of New Spain (not to be confused with the Viceroyalty of New Spain— named after the kingdom—which had a higher hierarchy and controller). The Audiencia was created by royal decree on December 13, 1527, and was seated in the viceregal capital of Mexico City. The First Audiencia was dissolved by the crown for its bungling and corruption and the crown established the Second Audiencia in 1530. Another Audiencia was created in Guadalajara in western Mexico in 1548.

Assertion of Royal Control

After the fall of Tenochtitlan in 1521 conqueror Hernán Cortés exercised power in New Spain as its first European governor and proceeded to allocate rewards to Spaniards who had participated in the victory. He initially established a government in the town of Coyoacán, south of Lake Texcoco, because Tenochtitlan was in ruins after the conquest. From here he governed with the title of Captain General and Justicia Mayor. In his letters to the king, he explained and justified his actions, arguing that it was necessary to grant rewards of encomiendas to conquerors in order to persuade them to remain in the area now under Spanish control rather than see them depart for conquests elsewhere.The crown sent treasury officials to New Spain, asserting the right of the crown to the revenues from the newly conquered lands. During Cortés's expedition to Honduras (1524–26), treasury officials were left in charge and the political situation descended into chaos. After Cortés's return to Mexico City in 1526, the crown realized that to assert its power over him that a higher level of royal authority was needed and created the Audiencia of Mexico.The first Audiencia in Mexico was created in 1528 and headed by crown official Nuño Beltrán de Guzmán. Hernán Cortés, who as leader of the Spanish conquest of the Aztec Empire, had accrued considerable wealth and power after the conquest that was not effectively checked by crown treasury officials. By setting up the Audiencia the crown sought to limit Cortés's personal power by creating the high court as an effective instrument of royal power.Guzmán was opposed by the first bishop of Mexico, Juan de Zumárraga, an ally of Cortés Guzmán's tenure as the president of the Audiencia was marked by ruthless attacks on his political rivals, corruption, and extreme violence against Indians. One scholar calls him "a natural gangster." However, structurally the crown had set up a conflictive situation between the conquerors turned encomenderos and the high court determined to assert royal authority. The crown's choice of Nuño de Guzmán as president of the Audiencia was a major blunder. Guzmán largely ignored the crown's instructions and intentions to assert royal authority against the conqueror group and their rewards with Guzmán acting as a rival to accrue power and wealth to himself and his retinue via the power of the Audiencia. The crown rectified its blunder and dissolved the First Audiencia in 1530 and established the Second Audiencia with judges who recognized crown authority; this body functioned until the end of the colonial era.

In 1532, the Viceroyalty of New Spain was created, although the first Viceroy, Don Antonio de Mendoza, would not arrive in Mexico until 1535. The Viceroy took over the executive functions of government from the Audiencia and served as its president. In the following decade, as more mainland areas were conquered, a second Audiencia was created in Guadalajara, the provincial capital of the Kingdom of New Galicia, in 1548.

Republic of Yucatán

The Republic of Yucatán (Spanish: República de Yucatán) was a sovereign state during two periods of the nineteenth century. The first Republic of Yucatán, founded May 29, 1823, willingly joined the Mexican federation as the Federated Republic of Yucatán on December 23, 1823, less than seven months later. The second Republic of Yucatán began in 1841, with its declaration of independence from the Mexican Federation. It remained independent for seven years, after which it rejoined the United Mexican States. The area of the former republic includes the modern Mexican states of Yucatán, Campeche and Quintana Roo. The Republic of Yucatán usually refers to the Second Republic (1841–1848).

The Republic of Yucatán was governed by the Constitution of 1841, one of the most advanced of its time. It guaranteed individual rights, religious freedom and what was then a new legal form called amparo (English: protection). The 1847 Caste War caused the Republic of Yucatán to request military aid from Mexico. This was given on the condition that the Republic rejoin the Mexican Federation.


Secession (derived from the Latin term secessio) is the withdrawal of a group from a larger entity, especially a political entity, but also from any organization, union or military alliance. Threats of secession can be a strategy for achieving more limited goals. It is, therefore, a process, which commences once a group proclaims the act of secession (e.g. declaration of independence). It could involve a violent or peaceful process but these do not change the nature of the outcome, which is the creation of a new state or entity independent from the group or territory it seceded from.

State governments of Mexico

State governments of Mexico are those sovereign governments formed in each Mexican state.

Structured in accordance with the constitution of each state, state governments in Mexico are modeled on the federal system, with three branches of government — executive, legislative, and judicial, and are formed based on the congressional system. Mexico's central federal government, on the other hand, represents the United Mexican States before international bodies such as the United Nations.

The executive power is exercised by the executive branch, which is headed by the state's governor, advised by a cabinet of Secretaries that are independent of the legislature. Legislative power is vested upon the congress of the state. Judicial power is exercised by the various local tribunals (Ministerio de Justicia) and the state's Supreme Court of Justice.

Territorial evolution of North America prior to 1763

Before contact with Europeans, the natives of North America were divided into many different polities, from small bands of a few families to large empires. Modern anthropology assigns some larger divisions into various "culture areas", regions within which a particular set of cultural, political, subsistence and/or linguistic traits predominated. These pre-Columbian American culture areas may also roughly correspond to particular geographic and biological zones of the continent. During the thousands of years of native inhabitation on the continent, cultures changed and shifted. One of the oldest cultures yet found is that of the Clovis peoples. Upon the arrival of the Europeans in the "New World", Native American population declined substantially, primarily due to the introduction of European diseases to which the Native Americans lacked immunity.There was limited contact between North American people and the outside world before 1492. Several theoretical contacts have been proposed, but the earliest physical evidence comes from the Norse or Vikings. Norse captain Leif Ericson is believed to have reached the Island of Newfoundland circa 1000 AD. In 1492 Columbus reached land in the Bahamas. Almost 500 years after the Norse, John Cabot explored the east coast of what would become Canada in 1497. Giovanni da Verrazzano explored the East Coast of North America from Florida to presumably Newfoundland in 1524. Jacques Cartier made a series of voyages on behalf of the French crown in 1534 and penetrated the St. Lawrence River. These powers slowly replaced the native nations of the North American east coast and then spread into the interior. The main powers in North America frequently fought over territory. One of the biggest wars was the French and Indian War that ended in France leaving the continent and giving up its claims in the Treaty of Paris. After 1763 a new power emerged, the independent United States of America.

Territorial evolution of North America since 1763

The 1763 Treaty of Paris ended the major war known by Americans as the French and Indian War and by Canadians as the Seven Years' War / Guerre de Sept Ans, or by French-Canadians, La Guerre de la Conquête. It was signed by Great Britain, France and Spain, with Portugal in agreement. Preferring to keep Guadeloupe, France gave up Canada and all of its claims to territory east of the Mississippi River to Britain. With France out of North America this dramatically changed the European political scene on the continent.

At first only the imperial powers of Europe had the resources to support and expand settlements in North America. As time went on the colonies became more powerful and sought independence from the Old World. These demands for more autonomy sparked several wars, including the American Revolutionary War (1775–1783) and the Mexican War of Independence (1810–1821). The last major colonial power on the continent, the United Kingdom, granted dominion status to Canada in 1867 and slowly turned over its remaining land to that country over the next 100 years, with the last land transfer being the Dominion of Newfoundland in 1949. Throughout this period, France maintained the small North American territory of Saint Pierre and Miquelon off the coast of the island of Newfoundland.From independence, the United States expanded rapidly to the west, acquiring the massive Louisiana territory in 1803 and fighting a war with Mexico to push west to the Pacific. At the same time, British settlement in Canada increased. US expansion was complicated by the division between "free" and "slave" states, which led to the Missouri Compromise of 1820. Likewise, Canada faced tensions between settlers, including French and English communities, and the colonial administration that led to the outbreak of civil strife in 1837. Mexico faced constant political tensions between liberals and conservatives, as well as the rebellion of the English-speaking region of Texas, which declared itself the Republic of Texas in 1836. In 1845, Texas joined the United States and in 1867 the United States acquired Alaska from Russia. The last major territorial change occurred when Newfoundland joined Canada in 1949, but there have been a number of small adjustments like the Boundary Treaty of 1970 where the city of Rio Rico, Texas, was ceded to Mexico.

By country
By former country
By region
By country, people, region or period
By international organisation

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.