The document discusses the US involvement in the Vietnam War under President Lyndon B. Johnson. It describes how the US initially provided support to France in fighting communist forces led by Ho Chi Minh. It then escalated its own involvement throughout the 1960s despite growing domestic opposition, leading to the deployment of 500,000 troops by 1968. The Tet Offensive in early 1968 was a major turning point that turned US public opinion against the war and led to LBJ deciding not to seek re-election.