History Day 2013-14 Timeline By facebooker_100001297234468 Period: Dec 19, 1946 to Aug 1, 1954 First Indochina War U.S. backs France to prevent a communist takeover May 11, 1961 400 U.S advisors in Vietnam Kennedy sends Green Berets to train ARVN Period: Feb 24, 1965 to Nov 1, 1968 Operation Rolling Thunder U.S. dropped 634,000 tons of bombs Jan 1, 1967 500,000 U.S. troops in Vietnam Jan 30, 1968 Tet Offensive launched by North Vietnamese Jan 27, 1973 U.S. troops begin to withdraw, ceasefire Apr 30, 1975 Saigon Falls