The Vietnam War, between North Vietnam and South Vietnam, lasted from approximately 1955 until 1975 and was fought with the goal of reunification. The North Vietnamese were aided financially and militarily by China and the Soviet Union, while South Vietnam was backed by the United States.

Regular U.S. deployments began after the 1964 Gulf of Tonkin incident. However, U.S. involvement peaked in 1968 following the Tet Offensive, which was an attempt by North Vietnam forces to execute surprise attacks on military and civilian command and control centers throughout South Vietnam. The Tet Offensive triggered the decline of support from the U.S. public, eventually dovetailing into the anti-Vietnam War movement. In May 1968, peace talks began between the United States and North Vietnam in Paris, France.

Gradual withdrawal of U.S. ground forces began in 1973 as part of "Vietnamization," a policy of President Richard Nixon's that sought to end American involvement by providing equipment and training to the South Vietnamese with the goal of transferring fighting solely to their forces. Additionally, President Nixon suspended military offensives against North Vietnam, and on January 15, 1973, direct U.S. involvement ended.

Despite all parties signing the Paris Peace Accords, fighting continued between North and South Vietnam, but South Vietnam was not able to sustain its defense against North Vietnam. The Vietnam War ended in April 1975 when the North Vietnamese Army captured Saigon, the capital city of South Vietnam. The countries reunified the following year.

Source and Further Reading:

Stanley Karnow, Vietnam: a history, New York: Viking Press, 1983.