[2] Clayton was elected as a Democrat to the United States House of Representatives of the 55th United States Congress and to the eight succeeding Congresses and served from March 4, 1897, until May 25, 1914, when he resigned and moved to Montgomery, Alabama to accept a federal judgeship.

[2] He was one of the managers appointed by the House of Representatives in 1905 to conduct the impeachment proceedings against Charles Swayne, Judge of the United States District Court for the Northern District of Florida, and in 1912 against Robert W. Archbald, Judge of the United States Commerce Court.

[2] He was appointed to the United States Senate to fill the vacancy caused by the death of United States Senator Joseph F. Johnston, but his appointment was challenged and withdrawn.

[1] He was confirmed by the United States Senate on May 2, 1914, and received his commission the same day.

[4] His brother, Bertram Tracy Clayton, was a United States Representative from New York.