James Fulton was elected as a Republican to the 79th United States Congress, and reelected to the 13 succeeding Congresses, serving from January 3, 1945, until his death from a heart attack in Washington, D.C. on October 6, 1971.

While in Congress he was delegated to the United Nations Conference on Trade and Employment at Havana in 1947 and 1948, and to the 14th General Assembly of United Nations in 1959. He was a delegate to 1956 Republican National Convention. In addition he served as an adviser on space to the United States Mission at the United Nations from 1960 to 1969.