The Battle of Ap Bau Bang (Vietnamese: trận Bàu Bàng) took place on the morning of 12 November 1965 when two regiments from the Viet Cong (VC) 9th Division attacked a night defensive position of the United States 2nd Battalion, 2nd Infantry Regiment (2/2nd Infantry) at a small village (ấp) by the name of Bàu Bàng, 25 km north of Thủ Dầu Một.
On 4 November the commander of the Army of the Republic of Vietnam (ARVN) 5th Division MG Phạm Quốc Thuần requested the 1st Infantry Division to secure Highway 13 north of Lai Khê to cover the movement of the ARVN 7th Regiment, 5th Division for an operation in the Michelin Rubber Plantation.
1st Infantry Division commander MG Seaman ordered Col. William Brodbeck's 3rd Brigade, 1st Infantry Division to undertake this mission. The mission in turn was given to Lt. Col. George Shuffer and his 2/2nd Infantry. Lt. Col. Shuffer established a Task Force consisting of his unit plus Troop A, 1st Squadron, 4th Cavalry Regiment and Battery C, 2nd Battalion, 33rd Artillery Regiment.:80 Lt. Col. Shuffer divided Highway 13 into 3 sectors each secured by a company and with the command group, Cavalry and artillery in the middle sector. Each day patrols would be sent out to sweep the Highway and its surroundings and they would withdraw into night defensive positions.:80
The commander of the VC 9th Division, Senior Colonel Hoàng Cầm decided to attack the American forces, gathering his units on the afternoon of 11 November. The main target would be the central American unit located just south of the village of Bau Bang, with the main assault by the 272nd Regiment supported by mortars and recoilless rifles and elements of the 271st Regiment. While the 273rd Regiment would attack from the south and block Highway 13 to the south preventing any reinforcement, while the 7th Battalion would be held in reserve.:81
On the night of 11 November several mortar rounds hit Lt. Col. Shuffer's central position and a night ambush killed 2 VC:81
At 06:05 on the morning 12 November, as Lt. Col. Shuffer's forces prepared to start patrolling Highway 13, the VC launched their attack. Starting with a barrage of 50 mortar rounds, a Battalion of VC attacked from the southwest. The attack was quickly met by return fire from Troop A's M113s which broke up the attack. A second attack from the south and a third attack from the southeast were similarly beaten back by the waiting American force.:83
At 07:00 the main attack was launched from the village of Bau Bang to the north and initially succeeded in penetrating the American position, before this attack was also repulsed. Battery C used its guns in anti-personnel mode firing 50 rounds at ground level with 2 second fuses. Air strikes by US Air Force A-1Hs and US Navy A-4s were directed against the VC mortars and recoilless rifles positioned in and around Bau Bang.:83–4
At 09:00 the VC launched a final assault from the north, but were met with concentrated artillery fire and air strikes and by 13:30 the Viet Cong had abandoned their attacks and withdrawn.:84
Total US casualties were 20 killed and 103 wounded, while VC losses were 146 killed (body count) and a further 50 were believed to have been killed, but the bodies were removed.:84 Vietnamese sources only acknowledged 109 killed and over 200 wounded for the VC and claimed to have killed or wounded 2000 Americans and destroyed 39 tanks and 8 heavy artillery pieces. The 2/2nd Infantry and attached units received a Valorous Unit Award for this action. 
The 4th Cavalry Regiment is a United States Army cavalry regiment, whose lineage is traced back to the mid-19th century. It was one of the most effective units of the Army against American Indians on the Texas frontier. Today, the regiment exists as separate squadrons within the U.S. Army. The 1st Squadron of the 4th Cavalry's official nickname is "Quarterhorse", which alludes to its 1/4 Cav designation. The 3rd Squadron of the 4th Cavalry's official nickname is "Raiders". Today, the "1st Squadron, 4th Cavalry", "2nd Squadron, 4th Cavalry", "4th Squadron, 4th Cavalry", and "6th Squadron, 4th Cavalry" are parts of the 1st Infantry Division, while the "3rd Squadron, 4th Cavalry" serves as part of the 25th Infantry Division. On 23 September 2009, the "4th Squadron, 4th Cavalry" officially stood up at Fort Riley, Kansas as part of the 1st "Devil" Brigade, 1st Infantry Division. On 28 March 2008, the "5th Squadron, 4th Cavalry" officially stood up at Fort Riley, Kansas as part of the 2nd "Dagger" Brigade, 1st Infantry Division. The 6th Squadron, 4th Cavalry served as part of the recently inactivated 1st Infantry Division, 3rd "Duke" Brigade, at Fort Knox, Kentucky.9th Division (Vietnam)
The 9th Infantry Division is a division of the People's Army of Vietnam (PAVN), first formed from Viet Cong units in 1964/5 in the Mekong Delta region.Operation Junction City
Operation Junction City was an 82-day military operation conducted by United States and Republic of Vietnam (RVN or South Vietnam) forces begun on 22 February 1967 during the Vietnam War. It was the largest U.S. airborne operation since Operation Varsity in March 1945, the largest airborne operation of the Vietnam War, and one of the largest U.S. operations of the war. The operation was named after Junction City, Kansas, home of the operation's commanding officer.Second battle of Bàu Bàng
The second Battle of Bàu Bàng occurred during the night of 19–20 March 1967 during Operation Junction City, a search and destroy mission by American military forces in Tay Ninh Province of South Vietnam, to the west of the capital Saigon.
Forces from the 5th Cavalry Regiment were entrusted with the securing of Fire Support Base 20, around 1.5 km north of the village of Bàu Bàng, and they had expected an attack, as their area was a known Viet Cong (VC) stronghold. During the evening of 19 March, the VC 9th Division attacked the base with machine guns, mortars, rockets and small arms fire. The mortars fired from afar while a large number of infantrymen dressed in black charged from the foliage. Initially, they swarmed over the American armored vehicles, but were dispersed by the vehicles shooting on one another, although some of the vehicles were destroyed. With the help of artillery and air strikes, as well as flares and aerial searchlights to spot their enemies, the Americans repelled the Viet Cong. They claimed 227 VC killed and captured three, while losing 3 and suffering 63 wounded.
Easter Offensive (1972)
Post-Paris Peace Accords (1973–1974)