The MACV was created on February 8, 1962, in response to the increase in U.S. military assistance to South Vietnam. MACV was first implemented to assist the Military Assistance Advisory Group (MAAG) Vietnam, controlling every advisory and assistance effort in Vietnam, but was reorganized on May 15, 1964 and absorbed MAAG Vietnam to its command when combat unit deployment became too large for advisory group control. The first commanding general of MACV, General Paul D. Harkins, was also the commander of MAAG Vietnam, and after reorganization was succeeded by General William C. Westmoreland in June, 1964, followed by General Creighton Abrams (July 1968) and General Frederick C. Weyand (June 1972). The MACV was disbanded on March 29, 1973.
Major component commands of MACV were: