Hugh Mulligan was said to have been a pretty tough guy who was quick with his fists and equally quick to pick up a gun to settle any disputes.
He aligned himself with New York’s Irish mob early on and became especially close with Eddie McGrath who elevated Mulligan as his second in command or underboss.
The Irish mob was first known as the Dunn-McGrath Gang and later became known as “The Arsenal Mob.” The gang was active in bootlegging and other rackets, but waterfront racketeering was to become the signature card of the Irish mob in New York.
In order to maintain peace within New York’s underworld community, Mulligan, under the direction of his boss McGrath, ”shared” connections with key members of New York’s notorious Five Families, especially the Vito Genovese Family.
It’s been said that Hughie Mulligan’s real strength, and by extension, the foundational strength of his Arsenal Mob lay in his ability to successfully penetrate and corrupt dozens of members of New York’s Police Department where he had close connections and friendships dating back years with many members of New York City’s then Irish-dominated police force.
And although Hugh Mulligan was very well known to the police, the prosecutor’s office, and the Federal Bureau of Investigation, he was scarcely known to the general public in the same way that many members of traditional organized crime families are as public figures.