The official representation began with the formal opening of diplomatic relations with the Holy See by President Ronald Reagan and Pope John Paul II in 1984.

President Jimmy Carter followed with the appointment of former New York City mayor Robert F. Wagner Jr. Every ambassador to date has been a member of the Roman Catholic Church.

President Franklin D. Roosevelt's Postmaster General James Farley was the first high-ranking government official to normalize relations with the Holy See in 1933 when the Postmaster General set sail for Europe, along with Soviet Commissar of Foreign Affairs Maxim Litvinoff on the Italian Liner SS Conte di Savoia.

[2] Myron Charles Taylor, an industrialist, philanthropist and diplomat (starting with World War II), served from December 1939 until 1950 as the personal representative of Presidents Franklin D. Roosevelt and Harry S. Truman to the Vatican.

[4] On October 20, 1951, Truman nominated Mark W. Clark, a U.S. Army general and World War II hero, to be emissary to the Holy See.

Senator from Massachusetts, Nixon's 1960 Republican vice presidential running mate and a former U.S. ambassador (to the United Nations, South Vietnam, and West Germany).