Wirtz continued to help run the Red Wings. In summer of 1951, Arthur Wirtz left Detroit to join the (Chicago) board of directors. In 1949, he and Jim Norris (the son of James) founded the International Boxing Club which presided over 47 of 51 championships through 1955. As Wirtz and Norris had control over most of the major sporting venues east of the Mississippi, federal authorities ended their boxing monopoly in 1958 and forced them to sell Madison Square Garden. In 1972, he partnered with Lester Crown from team founder Dick Klein and purchased a controlling stake in the Chicago Bulls In 1974, he lost a lawsuit brought by Milwaukee real estate magnate Marvin Fishman accusing him of illegally preventing Fishman's purchase of the Bulls.