Thomas J. Corcoran began his Foreign Service career in 1948. His first assignments abroad were in Spain and then, in 1950 in Hanoi and Hue in Vietnam, which was then under French control. He became the Chargé d’Affaires in Vientiane, Laos and then Phnom Penh, Cambodia in 1952. He went back to Hanoi from the beginning of September 1954 until about December 12, 1955. He was there about 14 months. He later served in Upper Volta, Haiti, and in Quebec, Canada and again in Vietnam for several years. He was Chargé d’Affaires ad interim (Laos) from August 1975 to March 1978 and he was ambassador to Burundi from 1978 until retiring from the State Department in 1980.