The united States ended it's involvement in the Vietnam war because of the Case–Church Amendment passed by the U.S. Congress. The capture of Saigon by the NVA in April 1975 marked the end of the war, and North and South Vietnam were reunified the following year.
The Vietnam War was an undeclared war in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975.
