The West Side of Manhattan, in New York City, had been associated with Irish gangsters long before Mickey Spillane, Jimmy Coonan, and Mickey Featherstone came along. Hell's Kitchen, an apt nickname for the Irish neighborhood during the 19th and 20th Centuries, was known to be a typical immigrant haven, that's residents were fiercely loyal to one another.
Hell's Kitchen photo above from WikiMedia Commons, courtesy of Jim Henderson. In the 1960s, the West Side of Manhattan was dying, and many believe the Westies gang, and other criminals, suffered the end of their enterprising when Hell's Kitchen was modernized.
For years, criminals used intimidation to extract money from the working people of the neighborhood. Their shakedowns expanded to the docks along the Hudson river, and they pressured labor unions to give them a fair share of dues - all for "protection". What was never said aloud was the Irish gangs offered protection from themselves, as well as the small-timers that might try shake downs of their own.
Mickey Spillane was the last big-shot gangster in Hell's Kitchen. He was running numbers rackets, loan sharking, and financing other criminals, but he walked around the neighborhood like a popular politician. Most of his time spent as boss of the Westies was lucrative and quiet. That's probably why his gang didn't draw the attention of law enforcement the way the gang that came after did.
The new guys, particularly Jimmy Coonan, were throwbacks, too. Unfortunately for their victims, they emulated the Irish gangs of yore that used violence to get what they wanted out of Hell's Kitchen, and they used it often and loudly. Guys from Coonan's Westies were bold, reckless, and merciless. They were just as likely to kill one of their own on the street as they were an outsider. Much blood was spilled during Coonan's reign, and his enforcer, Mickey Featherstone, was perhaps the coldest of them all.
Source: Public Domain
Jimmy Coonan, left, is incarcerated on RICO charges, and Mickey Featherstone, right, is in the US Government's Witness Protection Program.
Mickey Spillane's star in Manhattan began to fade as Coonan's group started to move in on his rackets. Spillane probably would have taken a peaceful road to retirement, if he hadn't been murdered on May 13, 1977. No one was convicted of Spillane's murder, but most believe it wasn't Coonan himself that did it.
What Coonan had that Spillane did not was an Italian connection. The Italian mobsters that operated in New York allowed the Irish Hell's Kitchen during Spillane's time. When Coonan started to woo over some of Spillane's gang to his own, the Italians reached out to him. In exchange for Gambino family sanction, Coonan would cut the Italians in on some of the Hell's Kitchen's extortion and other criminal rackets. The resulting alliance between Coonan and Gambino leader Big Paul Castellano is probably the biggest reason Spillane was murdered. He was the odd man out, and the only person standing in Jimmy Coonan's path to total criminal domination of Hell's Kitchen.