On 7 August 1964, the U.S. Congress passed the Gulf of Tonkin Resolution, a piece of enabling legislation that allowed President Johnson to undertake military action in Vietnam under the constitution. In 1964, communist forces in Vietnam appeared to be on the cusp of military victory against the government of South Vietnam. American forces had participated in the conflict between communists and anti-communists since the Truman administration and the American government stepped up its support of the South Vietnamese after the French withdrew in the mid-1950s. On 5 August 1964, an (allegedly) unprovoked attack on U.S. warships (Maddox and C. Turner Joy) in the Gulf of Tonkin gave President Johnson the pretext to expand the conflict. The U…
Richert, Lucas Paul. "Congress approves war against North Vietnam". The Literary Encyclopedia. First published 01 October 2008; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=3436, accessed 27 April 2015.]