Brien McMahon, born James O'Brien McMahon (October 6, 1903July 28, 1952) 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 Senate 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. Also, in 1952, McMahon proposed an "army" of young Americans to act as "missionaries of democracy", which sowed the seeds for what later became the Peace Corps. Early life and education McMahon was born in 1903 in Norwalk, Connecticut. McMahon graduated Fordham University in 1924 and then Yale Law School in 1927. McMahon changed his name to Brien McMahon the same year as being admitted to the bar. Justice career McMahon began a practice in Norwalk and later served as a judge on that town's city court, appointed to the position by Connecticut Governor Wilbur L. Cross. However, McMahon quickly resigned to become special assistant to the Attorney General of the United States in 1933. Attorney General Homer Cummings was also from Connecticut. In 1935, McMahon was appointed as United States Assistant Attorney General overseeing the Department of Justice's Criminal Division. Among prominent cases associated with McMahon in the Criminal Division were the prosecutions of John Dillinger's lawyer, Louis Piquette (for harboring a criminal) and the trials of gangsters associated with 'Baby Face' Nelson. However, the case that elevated McMahon to national renown and laid the foundation for his political career was the Harlan County Coal Miners' case. It was the first attempt to enforce the Wagner Act protecting unions. The case became famous, less for legal principles than for the violence and scandal surrounding the trial. Although he lost, he "received wide public recognition and a reputation as a courageous and honest upholder of justice, both of which would further his political ambitions," according to a biography accompanying the introduction to his papers, held by the Georgetown University Library. In 1939, McMahon left government service and resumed his law practice. In February 1940 McMahon married Rosemary Turner (June