The Vietnam War was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam (Democratic Republic of Vietnam) and South Vietnam (Republic of Vietnam) and their allies from 1 November 1955 to the fall of Saigon on 30 April 1975. This conflict was rooted in the Vietnamese struggle for independence from France. After France’s defeat, Vietnam was split along the 17th parallel by a Demilitarized Zone (DMZ). North Vietnam was supported by the Soviet Union and China, while South Vietnam was supported by the United States and other anti-communist nations. U.S. involvement escalated from advisors to combat troops on 4 July 1965 through 29 March 1973 when a peace accord led to U.S. withdrawal. North Vietnam subsequently conquered the South in 1975, unifying the country under communist rule.