From Wikipedia

Crime Inc.
Episode Two

Making of the Mob

Mafia groups in the United States first became influential in the New York City area, gradually progressing from small neighborhood operations in poor Italian ghettos to citywide and eventually international organizations. The Black Hand was a name given to an extortion method used in Italian neighborhoods at the turn of the last century. It has been sometimes mistaken for the Mafia, which it is not. Giuseppe Esposito was the first known Sicilian Mafia member to emigrate to the United States. He and six other Sicilians fled to New York after murdering eleven wealthy landowners, and the chancellor and a vice chancellor of a Sicilian province. He was arrested in New Orleans in 1881 and extradited to Italy.