The Vietnam War lasted 19 years and 180 days. The war lasted from Nov. 1, 1955 to April 30, 1975, according to the dates finalized by the Department of Defense in 1998. There was no formal declaration of war to start the Vietnam conflict.
The United States became involved in Vietnam shortly after World War II, sending funds and military advisers to aid the French. In 1954 the French were beaten and conceded defeat. On Nov. 1, 1955, the United States established the Vietnam Military Assistance Advisory Group to send military advisers to train and guide the South Vietnamese army and anti-communist forces directly. On April 30, 1975, North Vietnam captured the South Vietnamese capital of Saigon. The United States vacated the city the night before.