Joseph Valachi was a soldier in the Genovese crime family who became a significant figure in the history of American organized crime. In 1963, he became the first member of the Italian-American Mafia to publicly acknowledge its existence under the name 'Cosa Nostra'. His televised testimony before a U.S. Senate committee provided a wealth of information about the Mafia's structure, rituals, and operations. This act of breaking the code of omertà made him a pivotal government witness and led to the indictment of many powerful mobsters.