Born Giuseppe Esposito in Acerra, Italy (although other accounts claimed he was Sicilian), he joined one of the street gangs terrorizing Chicago's Little Italy during the early 1900s. When the Volstead Act (National Prohibition Act of 1919) was enacted, Esposito's organization, the 42 Gang, which included Sam Giancana and Paul Ricca, quickly entered into bootlegging. Esposito's early success with the Genna Brothers may have been a factor in the 1920 murder of rival "Big Jim" James Colosimo, a long time racketeer who had been hesitant to begin his own bootlegging operations.