The establishment of a Military Assistance Advisory Group in South Vietnam marks the beginning of American involvement in the conflict.

A Military Assistance Advisory Group (MAAG) is a designation for a group of United States military advisors sent to other countries to assist in the training of conventional armed forces and facilitate military aid. Although numerous MAAGs operated around the world throughout the 1940s–1970s, including in Yugoslavia after 1951, and to the Ethiopian Armed Forces, the most famous MAAGs were those active in South Vietnam, Cambodia, Laos, and Thailand, before and during the Vietnam War. Records held by the National Archives and Records Administration detail the activities of numerous assistance advisory groups.