By the early 1920s, Esposito earned another nickname, Diamond Joe, due to his frequent wearing of diamond cufflinks, diamond rings, and other jewelry. Esposito had become a
Republican ward boss of the Nineteenth Ward in Chicago. He was one of the earliest
Italian Americans elected as
aldermen. Esposito provided political protection to the bootlegging gangs of Chicago's Italian communities, including the South Side gang of mob boss
Johnny Torrio and the Genna brothers. In May 1921, Esposito famously attended the funeral of his political protégé
Antonio D'Andrea. Several years later, Esposito also attended the funeral of another criminal ally,
Angelo Genna murdered on May 25, 1925. ==Rivalry with Al Capone and death==