Viet Nam War

Armored cavalry assault vehicles move in file across a swampy jungle clearing in war Zone C, some 20 miles north of Tay Ninh on Feb. 24, 1967. The tracks of other tanks and armored vehicles are already imprinted into the high swamp grass, while infantrymen ring and seal off C zone in a horseshoe like deployment the armor pushes right into the heart of C zone from the south. (AP Photo/Kim Ki Sam)

ACAVs move in file across a clearing in War Zone C, along the Cambodian border, on Feb. 24, 1967. The tracks of other armored vehicles are already imprinted into ground. (AP Photo/Kim Ki Sam)

AP Photo/Kim Ki Sam