1908 - Jim Colosimo (? to May 11, 1920). "Big Jim" did not establish a Mafia family or even any sort of gang. He was a political arm-twister and a Chicago vice lord. Colosimo was, in fact, victimized by Black Handers and Mafiosi in Chicago. To protect himself, he brought a tough relative - Johnny Torrio - from the streets of New York out west to Chicago.
1919 - Torrio required some extra muscle to challenge existing gangs in Chicago. He sent for Alphonse Capone of Brooklyn.
1920 - Johnny Torrio (1882 to April 16, 1957). Colosimo, who had resisted Torrio's urgings to compete head-to-head with the Gennas in the bootlegging racket, was ambushed and killed in his offices on May 11, 1920.
1925 - Alphonse Capone (1899 to Jan. 25, 1947). Torrio was ambushed and severely wounded at his home on Jan. 24, 1925. He decided to retire and turned the gang operations over to Capone, who was brought west from Brooklyn. Torrio returned to New York City. (After a prison term for tax fraud, 1939 to 1941, he started a real estate business in Brooklyn.)
1930 - Capone gunmen killed Joe Aiello, eliminating Capone's last serious rival in the Chicago underworld.
1932 - Frank Nitti (? to March 1943). With Capone in prison on tax evasion charges, Nitti (left) took over day-to-day operations of the Outfit. Nitti was assisted by Paul Ricca and Tony Accardo.
1943 - Paul Ricca (Nov. 14, 1897, to Oct. 11, 1972). Nitti apparently committed suicide in March 1943. Ricca (right), also known as Paul DeLucia, took charge in Chicago briefly. Tony Accardo served as his underboss.
1944 - Tony Accardo (April 28, 1906, to May 27, 1992). Ricca was sent to prison, and Accardo was left to run the Outfit.
1947 - Released from prison, Ricca served as an adviser to Accardo. Some view Ricca as the actual boss, with Accardo playing the part of front man.
1956 - Sam Giancana (May 24, 1908, to June 19, 1975). Accardo retired as boss. Giancana took the helm.
1966 - Tony Accardo (April 28, 1906, to May 27, 1992). Giancana was forced to leave the country to escape prosecution. (Some say he was forced out more by Accardo than by prosecutors.) Accardo came out of retirement to once again lead the Chicago Outfit. He used Sam Battaglia as a front man. Battaglia was succeeded by Phil Alderisio and Jackie Cerone as screen for Accardo. Giancana returned years later, but his reputation had suffered due to his flight and his earlier misguided endorsement of John Kennedy's Presidential candidacy.
1974 - Giancana returned to Chicago.
1975 - Giancana was shot to death at his home in Oak Park on June 19, 1975.
1980s - Accardo retired to California.