Office of the Historian

Thomas Clifton Mann (1912–1999)

Career Foreign Service Officer
State of Residence: Texas
  1. Ambassador Extraordinary and Plenipotentiary (El Salvador)
    Appointed: October 11, 1955
    Presentation of Credentials: November 24, 1955
    Termination of Mission: Left post on September 24, 1957
    • Commissioned during a recess of the Senate; recommissioned on January 25, 1956, after confirmation.
  2. Assistant Secretary of State for Economic, Energy, and Business Affairs
    Appointed: September 7, 1957
    Entry on Duty: September 30, 1957
    Termination of Appointment: August 28, 1960
    • Commissioned during a recess of the Senate; recommissioned after confirmation on Jan 27, 1958. Designated Assistant Secretary of State for Inter-American Affairs on this date. A personnel action assigned Mann to the position of Assistant Secretary for Inter-American Affairs effective Aug 7, 1960, but this date was probably an error for Aug 28, 1960. Mann’s commission expired Apr 20, 1961.
  3. Assistant Secretary of State for Western Hemisphere Affairs
    Appointed: September 7, 1957
    Entry on Duty: August 28, 1960
    Termination of Appointment: April 20, 1961
    • Date of original commission as Assistant Secretary; prior to Aug 28, 1960, served as Assistant Secretary for Economic Affairs.
  4. Ambassador Extraordinary and Plenipotentiary (Mexico)
    Appointed: April 18, 1961
    Presentation of Credentials: May 8, 1961
    Termination of Mission: Left post on December 22, 1963
  5. Assistant Secretary of State for Western Hemisphere Affairs
    Appointed: December 21, 1963
    Entry on Duty: January 3, 1964
    Termination of Appointment: March 17, 1965
  6. Under Secretary for Economic Growth, Energy, and the Environment
    Appointed: March 11, 1965
    Entry on Duty: March 18, 1965
    Termination of Appointment: May 31, 1966