Brien McMahon (Born October 6, 1903, Norwalk, Connecticut - d. July 28, 1952, Washington, D.C.) was born James O'Brien McMahon. McMahon was an American lawyer and politician who served in the United States Senate (as a Democrat from Connecticut) from 1945 to 1952. McMahon was a major figure in the establishment of the Atomic Energy Commission, through his authorship of the Atomic Energy Act of 1946 (the McMahon Act). McMahon served as chairman of the Special Committee on Atomic Energy, and the first chairman of the Joint Committee on Atomic Energy. McMahon was a key figure in the early years of atomic weapons development and an advocate for the civilian (rather than military) control of nuclear development in the USA. McMahon was born James O'Brien McMahon in 1903 in Norwalk, CT. McMahon graduated Fordham University, New York City in 1924 and then Yale University Law School, New Haven, Connecticut in 1927. McMahon changed his name to Brien McMahon the same year as being admitted to the bar. McMahon began a practice in Norwalk and later served as a judge in the city. However, McMahon quickly resigned to become special assistant to the Attorney General of the United States in 1933. McMahon later served as United States Assistant Attorney General overseeing the Department of Justice's Criminal Division. Afterwards, he resumed his law practice for a brief while before being elected as a Democrat to the United States Senate in 1944. McMahon was reelected in 1950 and served until his death in Washington, D.C., 1952. McMahon is buried in St. Mary’s Cemetery in Norwalk.
A commemorative stamp honoring Brien McMahon and his role in opening the way to peaceful uses of atomic energy was issued by the United States on July 28, 1962 at Norwalk, CT. The stamp features a portrait of McMahon facing a rendition of an atomic symbol.
Brien McMahon High School, in Norwalk, is named after him.
