The 21st Infantry Division was formed in 1960 from the disbanded 11th and 13th Light Divisions and their personnel and equipment assigned to the new Division; the commander and staff of the 11th Light Division became the commanding general and headquarters elements of the new unit. The old headquarters of the 13th Light Division in Tây Ninh became the rear headquarters of the Division. The Division was responsible for the southwestern delta with an area of operations including Phong Dinh, Ba Xuyen,
Bạc Lieu,
An Xuyên and Chương Thiện provinces and the southern half of
Kiên Giang province, including the province capital,
Rạch Giá. Controlled by Military Region 3, four enemy regiments operated against the Division: the
Viet Cong (VC) D1 Regiment in Phong Dinh and the
People's Army of Vietnam (PAVN) D2, 95A Sapper and 18B Regiments in Chương Thiện. On 24 April 1962 the Division, supported by 16 Marine helicopters from
HMM-362, conducted Operation Nightingale near
Cần Thơ. 591 Division troops were landed to engage a VC force killing 70 and capturing three, while losing three killed.
1964 On 26 April the VC attacked a
Civil Guard post near
Kiên Lương district. The Division responded with three infantry battalions, an
M113 armored personnel carrier troop, and a Civil Guard company. The operation continued for two days. Sixty-two VC were killed, and air force pilots claimed to have killed another 47. Four VC were captured together with a 57mm recoilless rifle, a .50-caliber machine gun, and seven other weapons. Allied losses were 11 dead (including one US advisor), 43 wounded, and two M113s damaged. In June Brigadier general
Đặng Văn Quang became the Division commander. Quang was highly rated by his US senior adviser and was promoted to Major general in November. South Vietnamese President
Nguyễn Khánh described the incident as "a day of shame."
1966-1971 By 1967 Brigadier general
William Robertson Desobry, the US senior adviser in IV Corps, considered the division under Minh the best in the ARVN and the
9th Division not far behind. On 19 October 1969 the 32nd Regiment supported by helicopter gunships from the US
164th Combat Aviation Group engaged a PAVN/VC force in the
U Minh Forest south of Rạch Giá. At 11:00 another Division unit supported the fighting which continued until mid-afternoon when the PAVN/VC withdrew leaving 96 dead and 15 individual and six crew-served weapons and 145
Rocket-propelled grenades. An
AH-1 Cobra was shot down during the battle. In January 1970
John Paul Vann at the request of Ambassador
Ellsworth Bunker produced his own evaluations of IV Corps' commanders which differed markedly from the official judgments of MACV. Vann recommended all three division commanders and the special zone commander for relief, however only the 7th Division commander was replaced.
1972-1975 On 7 April 1972 at the start of the
Easter Offensive the Division was alerted for movement to
III Corps to support units of that Corps fighting in the
Battle of An Lộc. On 10 April the first elements of this division were already deployed to
Lai Khê. On the early morning of 30 April 1975, several RVNAF helicopters launched airstrikes to stop the VC from taking sections of the Arc Road Line. Later that morning President
Dương Văn Minh announced the
unconditional surrender to North Vietnam by radio. Hưng was upset about the surrender order and proposed that ARVN unit could retreat into the delta to continue fighting. Division soldiers retreated from the Arc Line to defend central Cần Thơ, but Hưng changed his mind and ordered them not to defend the city because of fears of the destruction that would result. At 20:00, the VC 9th Military Region representatives demanded the surrender of all ARVN units by the morning of 1 May. At 20:45 Hưng committed suicide at his home rather than surrender. On the morning of 1 May IV Corps commander Major general
Nguyễn Khoa Nam committed suicide at his headquarters. The Division was effectively disbanded on 1 May 1975. ==Organisation==