The U.S. Congress passes Public Law 88-408, which becomes known as the Tonkin Gulf Resolution, giving President Johnson the power to take whatever actions he deems necessary to defend Southeast Asia including "the use of armed force."
The resolution passed 82-2 in the Senate, where Wayne K. Morse (D-Oregon) and Ernest Gruening (D-Alaska) were the only dissenting votes; the bill passed 416-0 in the House of Representatives. President Johnson signed it into law on August 10. It became the legal basis for every presidential action taken by the Johnson administration during its conduct of the war. Despite the initial support for the resolution, it became increasingly controversial as Johnson used it to increase U.S. commitment to the war in Vietnam. It would be repealed in May 1970.