On July 27, 1921, at the end of his boxing career, Coulon married his diminutive Irish wife of over fifty years, Marie Maloney(1892–1984), a native Chicagoan. She never saw him fight professionally, but together they opened Coulon's Gymnasium on the South Side of Chicago around 1923. Marie was the business manager, and helped to match fighters who performed at the gym both as professionals and amateurs. Coulon's professional career was over when they met, but together they saw many of the great boxers train at their gym down thru the years — these included Jack Dempsey, Gene Tunney, Jim Braddock, Joe Louis, Sugar Ray Robinson, and Muhammad Ali." Ali would often use the gym to keep himself toned during his exile years. Coulon managed junior welterweight champion Eddie Perkins and light-heavyweight contender Allen Thomas. Coulon often travelled to find Perkins fights even into his 70s.