Rosenthal, born in Chicago, grew up in the city's West Side. As a youth, Rosenthal learned sports betting in the bleachers of Wrigley Field and would often skip classes to attend Chicago sporting events. By the mid-1950s, he was working with the Chicago Outfit. Chosen for his gambling ability, Rosenthal ran the biggest illegal bookmaking office in the U.S. on behalf of the American Mafia. Based in Cicero, Illinois, under the guise of the Cicero Home Improvement company, the Outfit and Rosenthal bought "contracts" from sports bribers to fix sporting events.
