U.S. Army Combat Arms Regimental System

The Combat Arms Regimental System (CARS), was the method of assigning unit designations to units of some of the combat arms branches (specifically, Infantry, including Special Forces, Field Artillery, and Armor) of the United States Army from 1957 to 1981. (Air Defense Artillery was added in 1968.) CARS was superseded by the U.S. Army Regimental System (USARS) in 1981.


Before the adoption of CARS, there was no satisfactory means of maintaining the active life of the combat arms organizations. Whenever the nation entered periods of military retrenchment, units were invariably broken up, reorganized, consolidated, or disbanded. During periods of mobilization, large numbers of new units were created. Changes in weapons and techniques of warfare produced new types of units to replace the old ones. As a result, soldiers frequently served in organizations with little or no history, while units with long combat records remained inactive.

In the late 1950s requirements for maneuverable and flexible major tactical organizations demanded highly mobile divisions with greatly increased firepower. For this purpose the regiment was deemed too large and unwieldy and had to be broken up into smaller organizations. (Most artillery and armored regiments had already been broken up for flexibility and maneuverability during World War II.)

When the U.S. Army division was reorganized under the Pentomic structure in 1957, the traditional regimental organization was eliminated, raising questions as to what the new units were to be called, how they were to be numbered, and what their relationship to former organizations was to be.

On 24 January 1957 the Secretary of the Army approved the CARS concept, as devised by the Deputy Chief of Staff for Personnel, which was designed to provide a flexible regimental structure that would permit perpetuation of unit history and tradition in the new tactical organization of divisions, without restricting the organizational trends of the future.

Units that participated in CARS

  • There were 61 Regular Army infantry regiments and 18 Army Reserve infantry regiments, plus the 1st Special Forces, in the Combat Arms Regimental System.
  • There were 30 Regular Army armor/cavalry regiments in the Combat Arms Regimental System. The only Regular Army combat units not organized under CARS were the 2nd, 3rd, 6th, 11th, and 14th Armored Cavalry Regiments.
  • There were 82 Regular Army artillery regiments in the Combat Arms Regimental System – 58 field artillery regiments and 24 air defense artillery regiments.
  • Except for the 18 Army Reserve infantry regiments, those regiments organized under CARS had elements in both the Regular Army and the Army Reserve. In the Army National Guard, each state has its own regiments. The number of CARS regiments varied as troop allotments change. The 1st Special Forces has elements in all three components – Regular Army, Army Reserve and Army National Guard.

The criteria for the majority of the regiments selected were two factors: age (one point for each year since original organization) and honors (two points for each campaign and American decoration). Those regiments with the most points were selected for inclusion in the system.

CARS implementation phases

  • Phase I: Reorganization of Regular Army regiments (1957)
  • Phase II: Reorganization of Army Reserve regiments (1959)
  • Phase III: Reorganization of Army National Guard regiments (1959)
  • Phase IV: Mobilization planning (1957–present)
  • Phase V: Organization of regimental headquarters (subsequently suspended indefinitely)


Each company, battery or troop in the regiment (as originally organized) was reorganized as the headquarters and headquarters element of a new battle group, battalion, or squadron in the new regiment. The new battle group, battalion, or squadron's organic elements (lettered elements, such as "Company A") were constituted and activated as new units. Each of the old companies, batteries, or troops of the former regiment also had the capability of becoming a separate company, battery, or troop in the new regiment. The regimental headquarters was transferred to Department of the Army control. (For detailed charts of typical regiments reorganized under CARS, see below Illustrations of organization under CARS)

The lowest numbered or lettered active element of the regiment normally has custody of the regimental properties. If, however, the lowest numbered or lettered active element is unable to care for the properties, they may be transferred to the next lowest numbered or lettered active element. If a numbered or lettered element of the regiment is activated lower than the one having custody of the regimental properties, the properties will not necessarily be transferred.

Difference between a brigade and a regiment

In a regiment not organized under CARS, there is a fixed number of organic elements organized into battalions or squadrons. For example, the infantry regiment of World War II contained twelve companies A through M (minus J - not used) divided into three battalions (of four companies each), plus supporting elements such as the service company.

A brigade, on the other hand, is a flexible organization; it has no permanent elements. A brigade may have several different kinds of units assigned to it, such as: three light infantry battalions or two mechanized infantry and an armor battalion or one light, one mechanized and one armor battalion; plus support units. The usual number of maneuver battalions was three; however, this was a guideline not a rule (ex: the 173rd Airborne Brigade in Vietnam had four airborne infantry battalions).

In tactical structure, therefore, it is very similar to the Regimental Combat Team of World War II and Korean War. Its maneuver (infantry and armor) elements were not required to be from the same regiment. Since they were flexible, except for the headquarters and headquarters company, no two brigades need be alike, whereas all regiments were fixed with organic elements provided for under basic tables of organization and equipment.

Battle honors

Each battalion or squadron of a CARS regiment has a replica of the regimental colors with the number of the battalion or squadron in the upper fly. The streamers attached to the colors were those for the regiment, as determined when the regiment was reorganized under CARS, plus those subsequently earned by the battalion or squadron.

Those campaigns and decorations actually earned by the battalion or squadron were shown on the streamers by earned honor devices. Regimental honors were listed on the battalion or squadron Lineage and Honors Certificates, with the earned honors being marked by asterisks.

Separate batteries, troops, and companies of CARS regiments display only those honors they actually earned, not the regimental ones. Campaign participation credit for these guidon-bearing units are displayed by silver bands and decorations streamers. (See ARs 672-5-1, 840-10 and 870-5 for further details.) Personnel wear the distinctive insignia for their regiment and the shoulder sleeve insignia of their division or other tactical organization to which they were assigned. (See AR 670-5 for further details.) The Adjutant General controls the designations of elements to be activated and coordinates his selections with the Center of Military History.

Regiments organized under Combat Arms Regimental System


Air Defense Artillery


Field Artillery

  • 1st Field Artillery
  • 2nd Field Artillery
  • 3rd Field Artillery
  • 4th Field Artillery
  • 5th Field Artillery
  • 6th Field Artillery
  • 7th Field Artillery
  • 8th Field Artillery
  • 9th Field Artillery
  • 10th Field Artillery
  • 11th Field Artillery
  • 12th Field Artillery
  • 13th Field Artillery
  • 14th Field Artillery
  • 15th Field Artillery
  • 16th Field Artillery
  • 17th Field Artillery
  • 18th Field Artillery
  • 19th Field Artillery
  • 20th Field Artillery
  • 21st Field Artillery
  • 22nd Field Artillery
  • 25th Field Artillery
  • 27th Field Artillery
  • 29th Field Artillery
  • 30th Field Artillery
  • 31st Field Artillery
  • 32nd Field Artillery
  • 33rd Field Artillery
  • 34th Field Artillery
  • 35th Field Artillery
  • 36th Field Artillery
  • 37th Field Artillery
  • 38th Field Artillery
  • 39th Field Artillery
  • 40th Field Artillery
  • 41st Field Artillery
  • 42nd Field Artillery
  • 73rd Field Artillery
  • 75th Field Artillery
  • 76th Field Artillery
  • 77th Field Artillery
  • 78th Field Artillery
  • 79th Field Artillery
  • 80th Field Artillery
  • 81st Field Artillery
  • 82nd Field Artillery
  • 83rd Field Artillery
  • 84th Field Artillery
  • 92nd Field Artillery
  • 94th Field Artillery
  • 319th Field Artillery
  • 103rd Field Artillery
  • 201st Field Artillery
  • 320th Field Artillery
  • 321st Field Artillery
  • 333rd Field Artillery
  • 377th Field Artillery


Regular Army regiments

Army Reserve regiments

Special Forces Regiment

Note: Army National Guard regiments not included

Illustrations of organization under CARS

Chart 1 – Typical Infantry rgt under CARS



Chart 2 – Typical Armor/Cavalry rgt under CARS



Chart 3 – Typical Field Artillery rgt under CARS



Chart 4 – Typical AD Artillery rgt under CARS




  • John K. Mahon and Romana Danysh, CMH 60-3: Infantry, Part I: Regular Army, The Pentomic Concept and the Combat Arms Regimental System
  • Department of the Army Regulations

Further reading

  • Department of the Army Publications
    • 672-5-1. Military Awards. 1974-06-03
    • 840-10. Flags and Guidons: Description and use of flags, guidons, tabards and automobile plates. 1962-08-23.
    • 870-5 Historical Activities: Military history – responsibilities, policies and procedures. 1977-01-22.
    • 870-20 Historical Activities: Historical properties and museums, 1976-09-28
    • _____. Circular 220-1. October 1960.
    • _____. Pamphlet 220-1. June 1957.
  • "America’s Pride: Famous Old Regiments to Get New Life," The Army Reservist, III (October 1957), 10-11.
  • "Army Studies Ways to Keep Famed Regiments on Roster," Army Times (28 April 1956), 7.
  • Atwood, Thomas W. "A Hard Look at CARS," Armor, LXXII (July–August 1963), 19-22.
  • Booth, Thomas W. "Combat Arms Regimental System," Army Information Digest, XII (August 1957) 24-31.
  • Bourjaily, Monte Jr. "Battle Honor ‘Lies’ ", Army Times (10 March 1962), 13.
  • _____. "Colorful Names Would Identify Regiments," Army Times (2 August 1958), 9.
  • _____. "The Combat Regiments," Army Times (16 July 1960), 15.
  • _____. "Is Regimental Plan a Paper Exercise?" Army Times (23 March 1957).
  • _____. "The Question of CARS," Army, XI (July 1961), 23-27.
  • _____. "Regimental Plan Can Live or Die," Army Times (16 February 1957).
  • _____. "Unit Homes in ’57?" Army Times (29 December 1956), 1, 35.
  • "CARS Confusion," editorial, Army Times (25 July 1959), 10+.
  • Corbett, W.H. "New Life for Old Regiments," National Guardsman, XII (April 1958), 8, 9; (May 1958), 4, 5.
  • Danysh, Romana. "What’s the History of Your Unit?" Army Digest, XXII (December 1967), 12-15.
  • Dupuy, R. Ernest. "Our Regiments will Live Forever," Army-Navy-Air Force Register, LXXVIII (September 1957), 3.
  • Eliot, George Fielding. "Army’s Future Tightly Linked to ‘Future of the Regiment,’ " Army Times (June 1955).
  • "Future of the Regiment," Army Times (4 December 1954); (11 December 1954).
  • Gavin, James M. "The Traditional Regiments will Live On," Army Combat Forces Journal, V (May 1955), 20-21.
  • Harrison, O.C. "Doubts About the Regimental System," Army, VII (July 1957), 62+.
  • _____. "The Combat Arms Regimental System," Armor, LXVI (November–December 1957), 18-21.
  • "Historic Regimental Designations to be Retained by the Army," Army Navy Air Force Register, LXXVII, 1.
  • Jones, F. P. "The Cost of Going Regimental," Army, XVII (May 1967), 47-49.
  • Keliher, John G. "CARS is OK. It Can Do the Job," Army, XI (May 1961), 70-71.
  • Kennedy, William V. "Continuity Through the Regiment," National Guardsman, XIII (February 1959), 2, 3, 31.
  • Lamison, K.R. and John Wike. "Combat Arms Regimental System," Army Information Digest, XIX (September 1964), 16-24.
  • Mahon, John K. and Romana Danysh. Infantry. ARMY LINEAGE SERIES. Washington: Government Printing Office, 1972. Pages 87–100.
  • McMahon, Walter L. "CARS ’75; Permanent Headquarters for the Combat Arms Regimental System." US Army War College Research Paper, 31 October 1974.
  • Palmer, Bruce Jr. "Let’s Keep the Regiment," Army Combat Forces Journal, V (May 1955), 22-23.
  • "Reserves Brought into CARS," Army Times (4 April 1959).
  • Schmieier, Elmer. "Long Live the Regiment," Army, VII (April 1957), 25-28.
  • Short, James Harvey. "Young Soldiers Fade Away." Student essay, US Army War College, 13 January 1967.
  • Sinnreich, Richard H. and George K. Osborn. "Revive the Regiment, Rotate, and Reorganize," Army, XXV (May 1975), 12-14.
  • Stubbs, Mary Lee and Stanley Russell Connor. Armor-Cavalry. ARMY LINEAGE SERIES. Washington: Government Printing Office, 1969. Pages 81–83.
  • Tallat-Kelpsa, Algis J. "A Regiment as Home for Career Soldiers," Army, XXI (January 1971), 51-52.
  • Wike, John W. "Our Regimental Heritage," Army Information Digest, XIX (February 1964), 50-56.
  • Organizational History Branch, United States Army Center of Military History
11th Armored Cavalry Regiment

The 11th Armored Cavalry Regiment ("Blackhorse Regiment") is a unit of the United States Army garrisoned at Fort Irwin, California. Although termed an armored cavalry regiment, it is being re-organized as a multi-component heavy brigade combat team. The regiment has served in the Philippine–American War, World War II, the Vietnam War, Cold War, Operation Desert Storm, and Operation Iraqi Freedom (Iraq War). The 11th ACR serves as the Opposing Force (OPFOR) for the Army and Marine task forces, and foreign military forces that train at the National Training Center.

The OPFOR trained U.S. Army forces in mechanized desert warfare following a Soviet-era style threat until June 2002, when the OPFOR and the 11th ACR changed to portraying an urban/asymmetrical warfare style of combat U.S. soldiers are facing in operations abroad. From June to December 2003, members of the 11th ACR deployed to Afghanistan, where they helped to develop and train the armor and mechanized infantry battalions of the Afghan National Army. These specialized units would defend the Afghan capital during the country's constitutional convention. In January 2004, the 11th ACR deployed to Iraq. The 11th ACR was not reorganized under the U.S. Army Combat Arms Regimental System, but has been reorganized under the U.S. Army Regimental System.

1st Cavalry Division (United States)

The 1st Cavalry Division ("First Team") is a combined arms division and is one of the most decorated combat divisions of the United States Army. It is based at Fort Hood, Texas. It was formed in 1921 and served during World War II, the Korean War, the Vietnam War, the Persian Gulf War, with the Stabilization Force in Bosnia-Herzegovina, in the Iraq War, in the War in Afghanistan and in Operation Freedom's Sentinel. As of October 2017, the 1st Cavalry Division is subordinate to III Corps and is commanded by Major General Paul T. Calvert.

The unit is unique in that it has served as a Cavalry (horse) Division, an Infantry Division, an Air Assault Division and an Armored Division throughout its existence.

1st Ranger Battalion (United States)

The 1st Ranger Battalion, currently based at Hunter Army Airfield in Savannah, Georgia, United States, is the first of three ranger battalions belonging to the United States Army's 75th Ranger Regiment.

It was originally formed shortly after the United States' entry into World War II and was modeled after the British Commandos during the war. Members from the unit were the first American soldiers to see combat in the European theater when they participated in the failed raid on Dieppe in France in 1942, during which three Rangers were killed and several more were captured. Later, the 1st Ranger Battalion was sent to North Africa where they participated in the landings in Algeria and the fighting in Tunisia in 1943. Also in 1943 the unit provided cadre for two more Ranger battalions created between the campaigns in Sicily and Italy. After World War II, the 1st Ranger Battalion has gone through a number of changes of name and composition as it has been activated, deactivated and reorganized on a number of occasions. However, the unit has lived on in one form or another since then, serving in the Korean and Vietnam Wars before being consolidated into the 75th Ranger Regiment of which it is a part today. Recent deployments have included operations in both Iraq and Afghanistan as part of the wider global war on terrorism.

327th Infantry Regiment (United States)

The 327th Infantry Regiment (Bastogne Bulldogs) is an infantry regiment of the 101st Airborne Division (Air Assault) of the United States Army. During World War II, the 327th was a glider-borne regiment of the 101st Airborne Division. It fought during World War I as part of the 82nd Division. It has also been deployed to: The Dominican Republic 1965; Vietnam, 7/29/65 – 3/10/72; Grenada, 1983; Panama, 1989; Desert Storm, 1990; and most recently to Iraq and Afghanistan. The song "Glider Rider" describes (humorously) some of the slights that glider-borne troops felt they received from the Army during World War II; though the regiment's public fame rose with the 1949 movie Battleground about the Siege of Bastogne in late 1944.

38th Air Defense Artillery Brigade (United States)

The 38th Air Defense Artillery Brigade is an inactivated United States Army unit which provided air defense for the Republic of Korea. Based at Osan Air Base from 25 May 1961 until 31 July 1981, its last assignment was as a major subordinate command in the Eighth United States Army. It was initially formed as the 38th Artillery Brigade in 1918.

4th Infantry Regiment (United States)

The U.S. 4th Infantry Regiment ("Warriors") is an infantry regiment in the United States Army. It has served the United States for approximately two hundred years.

71st Air Defense Artillery Regiment

The 71st Air Defense Artillery was a regiment in the United States Army.

75th Infantry Regiment (Ranger)

The 75th Infantry Regiment (Ranger) (officially 75th Infantry Regiment or 75th Infantry) was initially a parent regiment for all the US Army Ranger units during the Vietnam War and the early 1980s and then the headquarters for the Ranger battalions.


CARS may refer to:

Cable television relay service station

Car Allowance Rebate System, a.k.a. the Consumer Assistance to Recycle and Save program

Caucasian Achievement and Recognition Scholarship

Childhood Autism Rating Scale

Coherent anti-Stokes Raman spectroscopy

U.S. Army Combat Arms Regimental System a 1950s reorganisation of the regiments of the US Army

Confederation of Asia Roller Sports, a sports federation

Create a research space (CARS), a model for the structuring of research paper introductions

Customer Access and Retrieval System

Combat arms

Combat arms (or fighting arms in non-American parlance) is a collective name in a system of administrative military reference to those troops within national armed forces which participate in direct tactical ground combat. In general they include units that carry or employ a weapon system such as infantry, cavalry, and artillery units. The use of multiple combat arms in mutually supporting ways is known as combined arms.

In some countries, notably the British Army, the artillery units are categorised as combat support. Some armies such as the United States Army, classify combat engineers as a combat arm also, while armoured troops constitute a combat arm in name although many have histories derived from cavalry units. This is also true for the combat aviation units in many armed forces throughout the world.

Artillery is included as a combat arm primarily based on the history of employing cannons in close combat, and later in the anti-tank role until the advent of anti-tank guided missiles. The inclusion of special forces in some armed forces as a separate combat arm is often doctrinal because the troops of special forces units are essentially specialized infantry, often with historical links to ordinary light infantry units.

Combat service support

The term Combat service support (or CSS) is utilized by numerous military organizations throughout the world to describe entities that provide direct and indirect sustainment services to the groups that engage (or are potentially to be engaged) in combat.

Combat support

In the United States Army, the term combat support refers to units that provide fire support and operational assistance to combat elements. Combat support units provide specialized support functions to combat units in the areas of chemical warfare, combat engineering, intelligence, security, and communications.Combat support should not be confused with combat service support, which are units which primarily provide logistical support by providing supply, maintenance, transportation, health services, and other services required by the soldiers of combat units to continue their missions in combat. Expressed another way, Combat Support units are focused on providing operational support to combat units, while Combat Service Support units are focused on providing logistical support to combat units. Actual combat units are collectively referred to as combat arms units; hence, all army units fall into the category of either combat arms, combat support, or combat service support.

Field Artillery Branch (United States)

The Field Artillery is a combat arms branch of the United States Army.

Infantry Branch (United States)

The Infantry Branch (also known as the "Queen of the Battle") is a branch of the United States Army first established in 1775.

United States Army

The United States Army (USA) is the land warfare service branch of the United States Armed Forces. It is one of the seven uniformed services of the United States, and is designated as the Army of the United States in the United States Constitution. As the oldest and most senior branch of the U.S. military in order of precedence, the modern U.S. Army has its roots in the Continental Army, which was formed (14 June 1775) to fight the American Revolutionary War (1775–1783)—before the United States of America was established as a country. After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784 to replace the disbanded Continental Army. The United States Army considers itself descended from the Continental Army, and dates its institutional inception from the origin of that armed force in 1775.As a uniformed military service, the U.S. Army is part of the Department of the Army, which is one of the three military departments of the Department of Defense. The U.S. Army is headed by a civilian senior appointed civil servant, the Secretary of the Army (SECARMY) and by a chief military officer, the Chief of Staff of the Army (CSA) who is also a member of the Joint Chiefs of Staff. It is the largest military branch, and in the fiscal year 2017, the projected end strength for the Regular Army (USA) was 476,000 soldiers; the Army National Guard (ARNG) had 343,000 soldiers and the United States Army Reserve (USAR) had 199,000 soldiers; the combined-component strength of the U.S. Army was 1,018,000 soldiers. As a branch of the armed forces, the mission of the U.S. Army is "to fight and win our Nation's wars, by providing prompt, sustained, land dominance, across the full range of military operations and the spectrum of conflict, in support of combatant commanders". The branch participates in conflicts worldwide and is the major ground-based offensive and defensive force of the United States.

United States Army Rangers

The United States Army Rangers are designated U.S. Army Ranger units, past or present, or are graduates of the U.S. Army Ranger School. The term ranger has been in use unofficially in a military context since the early 17th century. The first military company officially commissioned as rangers were English soldiers fighting in King Philip's War (1676) and from there the term came into common official use in the French and Indian Wars. There have been American military companies officially called Rangers since the American Revolution.

The 75th Ranger Regiment is an elite airborne light infantry combat formation within the United States Army Special Operations Command (USASOC). The six battalions of the modern Rangers have been deployed in wars in Korea, Vietnam, Afghanistan, and Iraq, and saw action in several conflicts, such as those in Panama and Grenada. The Ranger Regiment traces its lineage to three of six battalions raised in World War II, and to the 5307th Composite Unit (Provisional)—known as "Merrill's Marauders", and then reflagged as the 475th Infantry, then later as the 75th Infantry.

The Ranger Training Brigade (RTB)—headquartered at Fort Benning—is an organization under the U.S. Army's Training and Doctrine Command (TRADOC) and is separate from the 75th Ranger Regiment. It has been in service in various forms since World War II. The Ranger Training Brigade administrates Ranger School, the satisfactory completion of which is required to become Ranger qualified and to wear the Ranger Tab.

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