In October 1963, the US 5th Special Forces Group established a small camp in the heart of the South Vietnamese Central Highlands at Plei Me in order to train indigenous Montagnard tribesmen for the South Vietnamese Civilian Irregular Defense Group (CIDG) initiative. The 450 CIDG troops at Plei Me, with 12 Americans of ODA-217 and 14 S. Vietnamese advisors, were tasked to gain civilian support among the Montagnards for the South Vietnamese war effort against Communist North Vietnam, and interdict Ho Chi Minh trail access routes along the Ia Drang River.
On 19 October, 1965, the 32nd Regiment of the North Vietnamese Army encircled the camp, while the 33rd Regiment waited for the inevitable relief column from the South Vietnamese army units outside of the city of Pleiku, 25 miles away. The 32nd Regiment came close to overrunning the camp but massive American air support, dropped as close as forty meters from the perimeter, defeated the NVA assaults.
That night the US airlifted 175 Vietnamese Rangers and US Special Forces, led by MAJ Charlie Beckwith, to reinforce the camp. And as the NVA predicted, the ARVN launched a 1400 strong armored task force from Pleiku. Over the next three days the NVA ambushed the column multiple times. Although there was heavy fighting, the combination of South Vietnamese armored firepower and American air support broke up the ambushes.
On 24 October 1965, the North Vietnamese commander broke off the siege and withdrew back toward his base camps around the Chu Pong Mountain near the Cambodian border. That same day, US General William Westmoreland ordered the recently arrived US 1st Cavalry Division, with its unprecedented air mobility through the use of helicopters, to pursue the North Vietnamese before they could escape across the Cambodian border.