During the 1920s and 1930s, U.S. cities such as New York and Chicago were at the mercy of bands of mobsters - violent criminals affiliated to organized-crime rings who made illegal fortunes from gambling, prostitution, contract killings, abortions, labor union kickbacks, protection rackets, bribery, corruption and, during the Prohibition era, bootlegging. While the Italian Mafia was the largest and most powerful, other ethnic groups had similar organizations, most notably the Jews and the Irish. Mobsters belonged to a hierarchical structure organized like a corporation, hence the name 'syndicate.' The Chicago Syndicate was the country's largest and most powerful organized-crime operation, although no one city was ever run by just one group and the different gangs often clashed violently in vicious territorial 'turf wars.' While their business interests and tactics have changed over the years, many of the organizations established in the gangsters' heyday prior to the Second World War still live on today under other names.