MAP ACTIVITYMap 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?