By mid-March 1975, with the PAVN's Spring Offensive underway, the ARVN enclaves at An Lộc and Chơn Thành were of no further military or political value and the 32nd Ranger Group defending An Lộc and the 31st Ranger Group defending Chơn Thành were needed to bolster the hard-pressed defenses throughout the region. Furthermore, the PAVN 273rd Infantry Regiment, 341st Division was discovered near Chơn Thành. To save the Rangers and RF in An Lộc and Chơn Thành, III Corps commander General Nguyễn Văn Toàn ordered an evacuation of An Lộc on 18 March. Among the first to be moved were 12 105 mm howitzers, while five of the 155 mm howitzers had to be destroyed because the Republic of Vietnam Air Force (RVNAF) did not have heavy-lift helicopters to move them. One Ranger battalion, the province headquarters and the III Corps Ranger Command were removed by helicopter, while the other two Ranger battalions and RF troops were to move south along Highway 13 to Chơn Thành. The overland force left on the night of 19 March and despite a few minor skirmishes arrived at Chơn Thành on 20 March.
