The Irish had the early political connections, and got into the unions first. They also became entrenched in the police and fire departments. They are to this day still influential in many unions. The Jewish mob got the most attention, with Meyer Lansky, Bugsy Seigel, and Lepke becoming legends, but the Irish got into so much so quickly, then were able to transition by passing it on to their friends, relatives, and sons without any taint attached. Lets also not forget that the Irish had the waterfront before the Italians did. Albert Anastasia was behind them on that, and they lasted much longer.