The 5th Marine Division was a United States Marine Corps infantry division which was activated on 11 November 1943 (officially activated on 21 January 1944) at Camp Pendleton, California during World War II. The 5th Division saw its first combat action during the Battle of Iwo Jima in 1945 where it sustained the highest number of casualties of the three Marine divisions of the V Amphibious Corps (invasion force). The 5th Division was to be part of the planned invasion of the Japan homeland before Japan surrendered. Assault troops of the 5th Division were included in the Presidential Unit Citation awarded to the V Amphibious Corps for extraordinary heroism on Iwo Jima from 19 to 28 February 1945. The 5th Division was deactivated on 5 February 1946.
The 5th Division was ordered to be reactivated on 1 March 1966 at Camp Pendleton, California, during the Vietnam War. The division, beginning with the reactivation of Regimental Landing Team 26 (RLT 26), was expected to be fully manned within one year; the 5th Division was never in command of the 26th Marine Regiment (26th Marines) in the war. In December, all three infantry battalions of the 26th Marines were fighting in Vietnam attached to the 3rd Marine Division. By June 1967, the 5th Division was ready to deploy anywhere. It was never intended that the 5th Division would go overseas. It was a force in readiness. But in February 1968, General William C. Westmoreland, U.S. Army, commander of U.S. forces in South Vietnam, asked for help because of the all-out Communist Tet Offensive. The 27th Marine Regiment (27th Marines), 5th Marine Division, was airlifted out on 48 hours notice, with 3,700 Marines. In September, it became the first major combat unit to come home from the Vietnam War. The 5th Marine Division formally deactivated on 26 November 1969.
Description
This campaign was from 2 April to 30 June 1968. During this period friendly forces conducted a number of battalion-size attritional operations against the enemy.
Operations PEGASUS-Lam Son 207 relieved the Khe Sanh Combat Base on 5 April and thereby opened Route 9 for the first time since August 1967. This operation not only severely restricted the North Vietnamese Army's use of western Quang Tri Province but also inflicted casualties on the remnants of two North Vietnamese divisions withdrawing from the area. This success was followed by a singular allied spoiling operation in the A Shau Valley, Operation DELAWARE-Lam Son. These two operations prevented the enemy from further attacking I Corps Tactical Zone population centers and forced him to shift his pressure to the III Corps Tactical Zone.
During the period 5-12 May 1968 the Viet Cong launched an offensive with Saigon as the primary objective. Friendly forces defended the city with great determination. Consequently Saigon was never in danger of being overrun. Small Viet Cong units that did manage to get into the outskirts were fragmented and driven out with great loss of enemy life. By the end of June 1968 friendly forces had decisively blunted the enemy's attacks, inflicted very heavy casualties, and hindered his ability to attack urban areas throughout the Republic of Vietnam. The enemy was forced to withdraw to his sanctuaries.
The strength of the U.S. Army in Vietnam reach a peak of nearly 360,000 men during this period.
