The Italian Mafia of the United States is one of the most famous criminal organizations in the world. Dozens of films have been made and hundreds of books written about it, but there are only a handful of works that describe the early history of what would later become the Cosa Nostra.
Mostly the reason why the things were like this was the influene of the lack of sufficient and reliable information about that period. Because of this the story of the appearance of the Mafia on the American continent, written during the information vacuum and still being replicated by mass media as the only true one, in practice is more of a myth than the real picture of what happened.
But fortunately for us, by now the researchers have received enough information about the circumstances to recreate more accurate history of that period.
So if you're interested in what Cosa Nostra was really like in its infancy in the United States, then give a reception, The Becoming of the New York Mafia, On the Other Side of the Law.
Primary sources:
"The First Family" - Mike Dash
Informer magazine is an issue about the early mafia. May 2014. Authors: Richard Warner, Angelo Santino, Lennert Vant Riet
David Critchley - "The Origin of Organized Crime in America"