around 1961 http://www.historyplace.com  America Commits: 1961-1964 Chronologie de la guerre du Viêt Nam, 1961-1964 16,000 military advisers "Vietnam War 1961–1964" Chronologie de la guerre du Viêt Nam, 1961-1964 who ordered thousands of U.S. troops to South Vietnam The History Place Timelines: 1961-64 John F. Kennedy sent 400 Green Berets to Vietnam