Guy Cooper became League Commissioner in 1948, succeeding his father, League pioneer Marshall Cooper, who had passed away the previous year. Guy Cooper's tenure as Commissioner was uneventful, with his most notable moments coming with an unsuccessful attempt to make the wearing of helmets mandatory, and the refusal to expand The League, turning down Stan "Tex" Coleman when he attempted to enter his Dallas Aztecs franchise into The League, laying the foundation for Coleman to start the Western League.

Cooper is best known for the scandal that broke in 1958, when a convicted mob boss implicated him in a gambling operation involving The League. Cooper was indicted, but fled the country before he could be prosecuted. The incident left The League's reputation badly damaged and suspect. Guy Cooper was succeeded as Commissioner by David Kent.