On this day in 1968, as part of the Tet Offensive, a squad of Viet Cong guerillas attacks the U.S. Embassy in Saigon. The soldiers seized the embassy and held it for six hours until an assault force of U.S. paratroopers landed by helicopter on the building’s roof and routed the Viet Cong.

The Tet Offensive was planned as a massive, simultaneous attack on the major cities and provincial capitals of South Vietnam. It was scheduled to take place during Tet, the Vietnamese lunar New Year celebration, which was traditionally a time of decreased fighting. In December 1967, following an attack on the U.S. Marine base at Khe Sanh, 50,000 American troops were sent in to defend the area, thereby weakening U.S. positions elsewhere. This American response played into the Viet Cong’s strategy to clear the way for the surprise Tet Offensive, in which Communist forces attacked Saigon, Hue (the imperial capital) and over 100 other urban areas.

The timing and magnitude of the attacks caught the South Vietnamese and American forces off guard, although they quickly recovered and recaptured the occupied areas. Militarily, the Tet Offensive was a disaster for the Communists, who suffered devastating losses. However, while the offensive was a crushing military defeat, the Communists scored a huge psychological victory that would ultimately help them win the war. The graphic images of U.S. casualties suffered during the offensive helped stoke anti-war sentiment among the American people, who had grown tired of the long conflict (active U.S. combat troops had been in Vietnam since 1965; the U.S. first sent in military advisers in 1961). The public was disillusioned by earlier overly optimistic reports of progress in the war and disenchanted with President Lyndon Johnson’s handling of it.

Johnson, frustrated with his inability to reach a solution in Vietnam, announced on March 31, 1968, that he would neither seek nor accept the nomination of his party for re-election. General William Westmoreland, commander of U.S. forces in Vietnam, requested an additional 206,000 troops to finish off the weakened enemy forces. Johnson denied Westmoreland’s request and replaced him with General Creighton Abrams. In May 1968, the U.S. and North Vietnamese began peace talks in Paris and reached a formal agreement in January 1973. Fighting between the North and South continued in Vietnam before the war finally ended on April 30, 1975, when Saigon fell to the Communists and the last Americans left Vietnam.