In response to a request from the U.S. Military Assistance Command in Vietnam, the division sent 100 helicopter door-gunners to South Vietnam in early 1963. By August 1965, further division involvement in the coming Vietnam War included the deployment of Company C, 65th Engineer Battalion, to South Vietnam to assist in the construction of port facilities at Cam Ranh Bay. By mid-1965, 2,200 men of the Tropic Lightning Division were involved in Vietnam.