Joe Masseria
What became known as the Castellammarese War began in early 1930 and dragged on for the better part of two years, as New York Mafia leaders Joe Masseria and Salvatore Maranzano fought for dominance over the New York rackets. Mineo felt secure being aligned with Joe Masseria, who led the most powerful New York Mafia crime family and was recognized as the most influential crime boss in the city. The Masseria-Mineo alliance quickly gained the upper hand in the war as their forces began to move on Castellammarese-controlled territories and rackets members, eliminating rivals at every opportunity, but on August 15, 1930, the tide began to change when Masseria's top advisor and war chief, Giuseppe Morello, was killed. Mineo was named Masseria's new war chief and strategist and quickly surmised that the Castellammarese were gaining more support and more ground as the war dragged on. Mineo felt the only solution was to find and kill Maranzano before he could kill Masseria, this being the only sensible solution to ending the war and re-establishing dominance over the New York Mafia.