Making Chicago mob overlord Tony Accardo mad was never a good idea.

So, when a crew of burglars had the audacity to break in to Accardo’s River Forest home in 1978 while he was out of town, they were hunted down by his underlings and, one by one, tortured and killed.

And Milwaukee’s longtime reputed mob leader Frank Balistrieri got into hot water with Accardo in the 1960s. That apparently was because Balistrieri’s people killed someone who wasn’t supposed to have been killed, according to records that are now part of the Chicago Sun-Times’ “The FBI Files” database.

But Balistrieri somehow weathered the crisis, staying alive until 1993, when he died of natural causes at 74, outlasting Accardo, who died in 1992 at 86 and had been an important mob figure since the time of Al Capone.

“On April 19, 1961, confidential informant T-6 advised” the FBI “that the Chicago hoodlum faction under Tony Accardo is feuding with the Balistrieri faction in Milwaukee,” according to the FBI records, which note that Milwaukee’s organized crime family, which Balistrieri led for several decades, ultimately was beholden to the Chicago mob.

“According to the informant, the reason for this quarrel goes back” to the murder of nightclub operator Izzy Pogrob “more than a year ago which was allegedly ordered by Frank Balistrieri.”

“The Chicago faction, according to the informant, did not want Pogrob’s murder and did not agree with his being killed,” the records show. “They are also angry because as a result of this murder police vigilance has increased to the point where the hoodlum element couldn’t get away with anything and aren’t making any money.”

The informant said Balistrieri was “saved from the Chicago group this long because he is the nephew of one of the big hoodlums in Kansas City and because [name blacked out] had apparently tried to talk the Chicago group out of doing anything” to Balistrieri.

The FBI records — publicly available because Balistrieri is dead, though with numerous redactions — delve into the Milwaukee mob’s connections to Accardo and the Chicago mob and show Milwaukee’s place in the grander organized crime syndicate that was a powerful force in America for the better part of the 20th century.

An informant “advised that the Milwaukee organization is under the direct supervision of the Italian Organization in Chicago, which is headed by Tony Acardo [sic]. He added that Acardo [sic] attends the yearly meeting of the Milwaukee organization,” according to the documents.

Balistrieri also promoted boxing events in Milwaukee, and Accardo “has a piece” of those “interests,” an informant told federal investigators.

Felix “Milwaukee Phil” Alderisio, a Chicago gangster, also was “a partner in just about everything that Frank Balistrieri has,” an informant told authorities in 1965.

Balistrieri’s business interests over the years included bars, restaurants and “strip tease” operations. He distributed “coin operated devices” including jukeboxes. He maintained veto power over large robberies and burglaries and sold stolen items, sometimes in Chicago, records show. He muscled legitimate businesses and individuals.

One of his establishments, a nightclub in Milwaukee called The Scene, had “considerable trouble with entertainers,” with rock ‘n’ roll legend Chuck Berry refusing “to appear until he was paid because Balistrieri was somewhat delinquent in his payments,” according to the records.

Balistrieri then called in someone whose name is omitted in the FBI records who “backed Chuck Berry in a corner and threatened him with physical violence unless he would appear. Berry did appear, but he was paid for his appearance.”

Balistrieri oversaw gambling in southeast Wisconsin and some of Chicago’s far north suburbs, according to FBI records which indicate that, in 1963, “Balistrieri met with syndicate members in Chicago” and struck a deal “to give him control of the illegal bookmaking operations in Northern Illinois, centering around Antioch, Pallatine [sic] and Zion.”

Probably Balistrieri’s highest-profile hustle involved Las Vegas casinos, which the mob secretly controlled and “skimmed” money from — until the feds blew the lid off the lucrative scam in the 1980s.

The case exposed links between mobsters in cities including Chicago and Kansas City — and it landed Balistrieri a lengthy prison sentence after he pleaded guilty to racketeering and conspiracy.

He’d only recently been convicted of gambling and extortion charges with the help of FBI agent Joseph Pistone, immortalized by Johnny Depp in the 1997 film “Donnie Brasco” chronicling Pistone’s New York undercover work.