The American Mafia (also referred to as simply the Mafia in the United States) is an Italian-American criminal society originating from the Sicilian Mafia. Much like the Sicilian Mafia, it has no formal name and is a secret criminal society. Members have often referred to it as Cosa Nostra or by its English translation "our thing." The Italian Mafia emerged in New York and other areas of the East Coast during the late 19th century thanks to waves of Italian immigration. While having its origins in the Sicilian Mafia, the organization grew into a pan-Italian organization, including North Italians from the French Empire, Neapolitans, Sardinians and Calabrians. The American Mafia still collaborates in a variety of criminal activities with the Sicilian Mafia and other Italian criminal organizations.
The American Mafia is currently strongest in the New York metropolitan area, Philadelphia and other major Northeast cities, as well as Chicago and the Detroit-Yorktown corridor. For most of the 20th century, however, they were the nation's most powerful criminal organization, with offshoots of major outfits in almost every major American city. Today, they are still regarded by the FBI as the United States' largest criminal organization. In particular, the FBI cites the Five Families of the New York-New Jersey area as the most powerful criminal organizations in the country.