The document provides background information on the origins and escalation of US involvement in the Vietnam War between 1940-1968. It discusses the colonial origins of the conflict, the rise of Vietnamese independence movements, and the increasing American economic and military support for France and later South Vietnam due to Cold War politics and the Domino Theory. Key events summarized include the US backing France until their 1954 defeat, the Vietnam being divided at the 17th parallel, the growth of the Viet Cong insurgency in the late 1950s, the Gulf of Tonkin incident leading to major US bombing campaigns and troop deployments in 1965-1967, and the Tet Offensive of 1968.