Besides his numerous other talents, Dion O'Banion was an excellent businessman. After the Torrio-Capone gang took over the Cicero city government in 1924, they assigned a small strip of that suburb to O'Banion, who had helped them in the conquest. He immediately quintupled bootlegging revenues in the area and began to extend his sphere of influence into the West side of Chicago, convincing saloon owners currently working with other gangs to buy their goods from him. Johnny Torrio demanded a cut of the new revenues, but O'Banion refused. O'Banion also made a habit of being a thorn in the side to a group of Torrio associates, the Genna brothers, who ran a large and vicious bootlegging enterprise centered in the West side. It was of the Gennas that O'Banion coined one of the most famous phrases in gangland history: "To hell with the Sicilians!"
Never cross a Sicilian.
Finally, in late Spring, 1924, Dion O'Banion could no longer contain his contempt for Torrio and his associates, and a plan to double-cross his boss took place at this location, currently the Near North Career Metro High School, but previously the site of the Sieben Brewery, jointly owned by O'Banion, Torrio, and Al Capone, located at 1464 N. Larrabee.
O'Banion had heard through the grapevine that the Sieben was scheduled for an upcoming police raid. Before that happened, he called a conference with his co-owners in the enterprise, Torrio and Capone, and announced that he was leaving the rackets, retiring to Colorado. Would they be interested in buying his share? Torrio and Capone readily agreed -- they were sick of the trouble and infighting O'Banion created, and would happily buy his train ticket out of the city.
There was just one more convoy of liquor to be delivered to the Brewery, on May 19, 1924, and after that, O'Banion was scheduled to hand over his interests in the business. Of course, O'Banion knew that that night was the planned evening of the raid. The police showed up and arrested both O'Banion and Torrio. Torrio was eventually sentenced to a nine-month prison sentence. O'Banion was murdered soon after, probably at the behest of Torrio, by Mike Genna and two other Sicilians, the famous assassins, Scalisi and Anselmi.
Thus began the great Beer Wars between the North Side Mob, under Dion O'Banion and his followers, and the Torrio-Capone Syndicate.