Why did the US enter the war in Vietnam and when?

Answer 1

It began in 1957 when President Eisenhower sent the first U.S. advisers to train the South Vietnamese armed forces in counter-insurgency tactics. The first big escalation was in 1965 under President Johnson, with transfer of the 173d Airborne Brigade, followed by several entire combat divisions.

Answer 2

Part of the cold war; to stop communist aggression. President Eisenhower deployed US Military personnel to South Vietnam, in phases, to establish a firm con-communist government in 1954; in 1955 more US troops were in country to assist the newly formed South Vietnamese government in defending itself against communist infiltration.

Answer 3

Military advisors were deployed to South Vietnam in the 1950s under Eisernhower. When North Vietnam escalated aggression against the South in 1961 John Kennedy sent more advisors.