Joseph C. O'Mahoney as a United States Senator (Democrat) from Wyoming.
O'Mahoney was born in Chelsea, Suffolk County, Massachusetts, November 5, 1884. He attended the parochial and public schools and Columbia University, New York City. He moved to Boulder, Colorado in 1908 and engaged as a reporter on the Boulder Herald; moved to Cheyenne, Wyoming in 1916 and served as city editor of the Cheyenne State Leader.
O'Mahoney was executive secretary to Senator John B. Kendrick 1917-1920. He graduated from the Georgetown University Law School, Washington, D.C., in 1920. He was admitted to the bar in 1920 and commenced practice in Cheyenne, Wyoming and Washington, D.C.. He was a member of conference on uniform State laws 1925-1926 and a city attorney of Cheyenne, Wyoming from 1929-1931.
O'Mahoney was a Democratic National Committeeman from 1929-1934. He was appointed First Assistant Postmaster General in 1933 and served until December 31, 1933, when he resigned to become a Senator. He was appointed on December 18, 1933 as a Democrat to the United States Senate to fill the vacancy caused by the death of John B. Kendrick, and elected on November 6, 1934, to fill this vacancy and also for the term commencing January 3, 1935. He was reelected in 1940 and again in 1946, and served from January 1, 1934, to January 3, 1953.
O'Mahoney was chairman of the Committee on Indian Affairs (Seventy-eighth and Seventy-ninth Congresses), Committee on Interior and Insular Affairs (Eighty-first and Eighty-second Congresses), co-chairman, Joint Committee on the Economic Report (Eighty-first and Eighty-second Congresses); unsuccessful candidate for reelection in 1952; elected on November 2, 1954, to fill the vacancy caused by the death of Lester C. Hunt, and also elected for the full term commencing January 3, 1955, and served from November 29, 1954, to January 3, 1961; was not a candidate for renomination in 1960; resumed the practice of law in Washington, D.C., and Cheyenne, Wyoming.
O'Mahoney died in the naval hospital, Bethesda, Maryland on December 1, 1962. His remains are interred in Mount Olivet Cemetery, Cheyenne, Wyoming.
Preceded by: John B. Kendrick U.S. Senator (Class 1) from Wyoming 1934 - 1953 Succeeded by: Frank A. Barrett