In 1961, Billings declined Kennedy's offer to appoint him the first head of the Peace Corps, director of a new agency to promote tourism, the U.S. Travel Service, or ambassador to Denmark. He later said: "I realized that I did not want to work for the president — because I felt it would change our relationship." In September 1961, he accepted an appointment to the board of trustees of the planned National Cultural Center, which later became the Kennedy Center. The next year, Kennedy named him to a board to plan America's participation in the New York World's Fair of 1964–5. He represented the President when the alumni association unveiled Kennedy's portrait at Choate in May 1963.