Vietnam War By 18120 Jan 1, 1954 Dien Bien Phu The Viet Minh defeated the French rule in Vietnam. Jan 1, 1954 Vietnam is split in half Mar 15, 1955 U.S gets involved in the war They are aiding South Vietnam. Aug 1, 1964 Gulf of Tonkin Incident Feb 1, 1965 U.S started operation Rolling Thunder Jan 1, 1968 Tet Offensive Mar 1, 1968 Mai Lai Massacre Nov 1, 1969 U.S public found out about the Mai Lai Massacre Jan 1, 1973 U.S leaves Vietnam Mar 15, 1975 Vietnam becomes communist South Vietnam surrender to Ho CHi Minh.