Dennis Johnson, 38, of Plainfield was also given three years' probation following his release for his part in the video gambling racket run out of suburban Cicero by suspected mobster Michael "Mickey" Marcello.
U.S. District Judge James B. Zagel said that although Johnson was not the mob leader that some of his co-defendants were, he was instrumental in a multimillion-dollar scheme.
Zagel sentenced Johnson to the minimum under the federal guideline range, saying he deserved credit for pulling himself together and changing his lifestyle since pleading guilty in June 2007.
Prosecutors did not press for a stiff sentence. "He was a small cog in the large wheel of the Outfit," said Markus Funk, one of three prosecutors who secured convictions against suspected top-echelon Chicago mobsters at the trial.
The case is one of the biggest targeting organized crime in Chicago. Defendants are accused of operating the Chicago Outfit - another name for the city's organized crime family - as a racketeering enterprise.
Johnson and his brother, Thomas Johnson of Willow Springs, both worked for Marcello's Cicero-based M&M Entertainment.
The two acknowledged they altered video games so they could be used as gambling devices, placed them in taverns and clubs, and collected the proceeds. Bogus records hid the profits, they said.
Thomas Johnson and Marcello have also pleaded guilty. Thomas Johnson is awaiting sentencing. Marcello got eight years after admitting he tried to buy the silence of jailed mobster Nicholas Calabrese - the government's star witness - by paying his wife $4,000 a month in hush money.