Some of the most well-known and notorious gangsters of the 1940s included Al Capone, Frank Costello, Lucky Luciano, Meyer Lansky, Bugsy Siegel and Tony Accardo. These men did their dirty work mostly in Chicago.
One notorious gangster of the era was Frank Costello. He was named the acting boss of the Luciano crime family in 1936 after Lucky Luciano was sent to prison. Throughout the early 1940s, Costello prospered as the head of the family, earning himself the nickname "Prime Minister of the Underworld." Another one of the most well-known gangsters of the era was Meyer Lansky, infamous for his gambling empire and role in creating the National Syndicate. Lansky was reportedly behind the murder of yet another famous gangster of the '30s and '40s, Benjamin "Bugsy" Siegel. Bugsy was in charge of constructing the Flamingo Hotel and Casino in Las Vegas, but was killed at his home in Beverly Hills in 1947.
Undoubtedly the most famous mobster was Al Capone, whose illegal activities such as bootlegging, prostitution, loan sharking and numbers, earned him the nickname "King of the Underworld." Tony Accardo, one of the shrewdest crime figures of the 1940s, was appointed as an underboss for the Chicago-based Capone crime family in 1943, and helped move the family business away from the more violent methods of income, instead relying on slot machines, counterfeit cigarettes and narcotics trafficking to fund the empire. This move kept the Capone family incredibly profitable and relatively safe from prosecution for years. Accardo was one of the few mobsters who died later in life of natural causes, finally succumbing to heart and lung disease on May 27, 1992.