The Gulf of Tonkin
On August 2-3, 1964, North Vietnamese gunboats attacked the American naval warship, the USS Maddox in the Gulf of Tonkin off the coast of North Vietnam. President Lyndon Johnson ordered retaliatory air strikes. Five days later, Congress passed the Gulf of Tonkin Resolution, giving Johnson the power to take whatever actions he saw as necessary. By the end of 1966, Johnson had sent in 389,000 troops.