The correct answer is 1973. Here's an explanation:
1. The United States pulled the last of their troops from Vietnam in 1973.
2. This withdrawal was part of the Paris Peace Accords signed in January 1973, which aimed to end the involvement of U.S. military forces in the Vietnam War.
3. The agreement included the withdrawal of U.S. troops and the release of prisoners of war.
4. The fall of Saigon, the capital of South Vietnam, occurred in 1975, leading to the unification of North and South Vietnam under communist rule.
In summary, the United States officially removed the last of their troops from Vietnam in 1973 as part of the Paris Peace Accords.
