In 1959, FBI agents planted a microphone in a room at the Armory Lounge in the suburb of Forest Park, which served as Giancana's headquarters.
For the next six years, they were able to eavesdrop on the workings of the Mafia and gain knowledge of many criminal activities in Chicago and around the country.
Giancana himself was killed before giving testimony.
Gangster and crime boss Sam Giancana was born Gilormo Giancana, on June 15 (some sources say May 24), 1908, in Chicago, Illinois.
Though Giancana's reign as Chicago's preeminent crime boss was already heading towards its end by the close of the 1950s, his path in the 1960s would cross with two of America's most powerful men: Robert and John F. After Angeline's death in 1954, Giancana became notorious for his flamboyant social life and frequent womanizing.