In these movies, the mafia has their roots in Sicily. From what I know about Italian history and having spoken to several Italians throughout the years, Italy was/is a very fragmented place, not having been unified until the 1870s. Even today, many Italians I speak to tell me that there is still some tension between the different regions, with Northern Italians looking down on Southern Italians and Sicilians and vice versa.
So, back to my question. In the movies and in pop culture, they constantly talk about needing to be of pure Italian extraction to be "Made". If the mafia is mostly Sicilian, as the movies indicate, could a person from let's say Florence have been "Made"?
It all depends on who you ask. According to Joseph Valachi, whose 1963 testimony shaped law enforcement and public perceptions of the Mafia, the only requirement for membership was that one had to be “full Italian,” i.e., both parents of Italian heritage. He made no mention of a Sicilian requirement. Indeed, many New York mobsters, up to and including Frank Costello, the reputed boss of all bosses of the Mafia from the 1930s to 1957, were not Sicilian (Costello was Calabrian). Al Capone’s family hailed originally from Salerno.
In Italy, the Mafia developed in 19th century Sicily, and the writings of Mario Puzo popularized the links between Sicily and the Mafia. So it would make sense to speak of the Mafia as a Sicilian organization, and strictly speaking it was a Sicilian concept. But in practice, organized crime in the United States, whether it was known as the Mob, the Mafia, or La Cosa Nostra, was not limited to Sicilians.