The Castellammarese War was one of the most vicious and deadly war seen in the American history. This war started from 1929 and ended in 1931. The war was basically was a power struggle for the Italian-American Mafia. The two warring faction were the Masseria faction headed by Joe Masseria and the Maranzano faction headed by the Salvatore Maranzano. In the end the Maranzano faction won and Salvatore declared himself as the “boss of all bosses” (Abadinsky, 2016).