Mahaffey was born in Williamsport, Pennsylvania, and educated there. He attended Media University, after which he became an accountant and was employed by the Pennsylvania Railroad Company. He moved to Los Angeles in 1902 and became affiliated with the Hollywood Lumber Company. In Hollywood he was director of the Hollywood Board of Trade and later became president of its successor, the Hollywood Chamber of Commerce. He was also president of the Hollywood Kiwanis Club and was in the Masons. "Supervisor Mahaffey Expires From Heart Ailment," Los Angeles Times, April 10, 1932, page A-2"Mahaffey Laid to Rest," Los Angeles Times, April 12, 1932, page A-2
