MAP ACTIVITY Map 29.2 The Vietnam War, 1964–1975 The United States sent 2.6 million soldiers to Vietnam and spent more than $150 billion on the longest war in American history, but it was unable to prevent the unification of Vietnam under a Communist government. READING THE MAP: What accords divided Vietnam into two nations? When were these accords signed, and where was the line of division drawn? Through what countries did the Ho Chi Minh Trail go? CONNECTIONS: What was the Gulf of Tonkin incident, and how did the United States respond? What was the Tet Offensive, and how did it affect the war?