In a small mining community in Depression-era Illinois, Charlie Jacobs convinces his best friend, Thaddeus Winowski, to quit the poverty and drudgery of the coal mines and strike out on their own by imitating infamous gangster Al Capone. In his shabby room, Charlie impresses Thad with the crisp new fedora and pin-stripped suit he has saved for months to purchase from the Sears catalog. Charlie then asks Thad to be his bodyguard and his grateful friend accepts. The next day, Charlie and Thad pay a call on the town sheriff, Harve Koontz, to confide their plan and offer him a bribe to ignore their impending law-breaking. Initially Harve refuses, citing responsibility to his legal oath, but when his wife Hilda overhears Charlie’s offer, she insists that her poorly paid husband accept. Afterward, Harve warns Charlie and Thad about the zealous law-and-order obsessed Ku Klux Klan members led by the driven Clay Farrell, but the pair ignores him and use their meager savings to start a loan shark business. When their former friends and miners cannot repay any of the loans, and Charlie and Thad deplete their savings, Thad grows despondent, but Charlie insists they only have to rob someone to replenish their funds. Pretending to have pistols, the pair confronts a man in an alley but are crestfallen when he ignores them and walks away. Undaunted, Charlie decides they should move on to the next little town where they are unknown. In the next town, however, Charlie and Thad come across Farrell giving a speech to several locals and hooded Klan members. Offended that the Klan targets Jews, Charlie and Thad turn away but are stopped and beaten by Farrell’s thugs. Promptly jailed with Farrell for disorderly behavior, Charlie convinces the overweight police captain that he is the point man for Capone’s gang. Promising to give him an important position in Capone’s organization, Charlie wins his and Thad’s release while Farrell complains bitterly. On their way out, Charlie and Thad run into old friend Lottie Cragmore, who has been arrested for drunkenness. Promising to look after her, the men take Lottie to a boardinghouse run by Charlie’s acquaintance, Penny. After Lottie passes out in a drunken stupor, Charlie discovers a will in her coat leaving her a restaurant and the surrounding property. After briefly considering becoming either Lottie’s pimp or husband to gain access to the restaurant, Charlie decides that he should convince Lottie to let him turn the property into a roadhouse offering gambling and liquor. Certain that a proper roadhouse will need “dames,” Charlie visits the local whorehouse to learn how it is run and offer a job to their top prostitute, but is frightened off when the woman greets him with a song. When Charlie returns, he decides that they need a car. The men wander into town and stake out a parking lot, then select a car, unaware that it belongs to Farrell, who is conducting a Klan meeting next door. Furious, Farrell gives chase, but Charlie and Thad escape. While driving to Lottie’s property in Farrell’s car, Charlie, Thad and Lottie spot a young man sitting on a flag pole and pull over. The man’s associate, standing below, explains that they are trying to win a contest and prize money. Charlie asks the men to join his gang and when he assures them women will be involved, they give up their contest and jump into the car. Several miles on, Charlie spots an exhausted couple staggering down the road and recognizes eccentric Claude Westinghouse, a formerly wealthy inventor who has fallen on hard times. After Claude admits he and his worn-out partner Billy are attempting to establish a long-distance dance record, Charlie invites him to join the gang and, leaving the unconscious Billy by the wayside, Claude enthusiastically accepts. Upon arriving at Lottie’s property, which she calls “Sadie’s Rest” after the woman who willed it to her, Charlie and the others take stock of its dilapidated condition. Charlie agrees with Claude’s practical declaration that they need money to make repairs and declares they will rob a bank. Delighted, Claude draws up plans, and the next day the men, armed with shotguns and a tommy-gun, burst into the town bank only to discover it is closed for redecorating and all the money has been transferred to another branch. When Charlie and Claude insist they intend to rob something, the manager, Mr. Babcock, politely takes them around the bank until they find one safe-deposit box, which they happily steal. Later, Charlie visits Harve to pay him his bribe money just as the sheriff receives an outraged phone call from Farrell reporting the theft of his safe-deposit box. Back at the house, an embarrassed Claude reveals that Billy and other former girl friends have tracked him down, but Charlie encourages him to put them up in the small shack behind the main house. After Farrell leads a group of Klansmen to the house to demand that the gang leave town in twelve hours, Charlie and Claude take Claude’s small airplane aloft and, spotting Farrell leading a hillside cross burning, hurl the empty box at him. A few days later, Charlie and the others are excited when a reporter and photographer arrive at the house, explaining that word of their odd exploits has spread. After offering Charlie some advice on restoring the house, the reporter summons the gang who, dressed in their finest, pose for a picture on and around the car while Claude dubs them Charleston Charlie’s Clan. A few days after the article on the gang is printed, Harve visits the house to warn that Farrell has lodged a legal complaint against Charlie for attacking him. After a professional hoodlum, “Violin” Polanski, arrives offering to sell them weapons, the pacifist Charlie suggests that the gang should voluntarily go to jail for three days to appease Farrell. That afternoon, Farrell and the police captain burst into the sheriff’s office to inform Harve he has been relieved of duty and demand Charlie’s legitimate arrest. The captain’s men and Klan members take Harve and Charlie to the police jail, where Penny visits the next day to warn Charlie that Farrell wants to lynch them. Soon after, a group of hooded men arrive at the jail and force the captain to release Charlie and Harve. Outside, however, Charlie realizes the men are his gang members in disguise. Running away just as Farrell and his men are marching up the street, they make their getaway, planning to build up the roadhouse and be the best gang in Southern Illinois.