I was born and have lived in Decatur, IL my whole life. Most of you have probably never heard of it, but it's directly central in Illinois and has a population of about 75,000-76,000. There's a pretty high crime rate out here. For as long as I can remember, everyone here has called it "Little Chicago". I guess it was also a fairly speak-easy town during prohibition. Supposedly guys from The Outfit and gangsters from St. Louis used this place as a cool off spot. I don't know if I necessarily believe that but I'm a member or two from The Outfit has been out this way. Also supposedly Al Capone came here a time or two...I don't believe that one lol.
One more piece of trivia:
There's a very small town called Maroa about ten or fifteen miles from Decatur; Dion (Dean) O'Banion was born there.
I saw a book on amazon called "Wicked Decatur"; the introduction says in the 10s and 20s it had the second crime rate in the state after Chicago. Have you read it, is it interesting?
By the way, did Decatur have a mafia representative or any other crime boss (even if not Cosa Nostra) who controlled the whole city during prohibition?