According to the novel, Sollozzo was a Sicilian, not an American. He was evidently a major drug wholesaler in Europe and the Middle East, seeking to establish a strong partnership for retail drug trafficking in the US. He was not a member of any Mafia family in the US--but presumably, if he had been successful, he would have become a power in the US Mafia.
There is no direct analog to Sollozzo in US Mob history. The only connection I can make is with Cesare Bonventre and Sal Catalano, two Sicilians (called "zips") who were brought to the US to head a major heroin racket by Carmine Galante when he was the Bonanno Don. However, the "zips" became actual capos in the Bonanno family. Bonventre later made a bid to head the Bonannos but lost out in the war that was described in the book, "Donnie Brasco."
