[2] In 1919, the Gennas became involved in bootlegging; they obtained a federal license to legally manufacture industrial alcohol, which they sold illegally.
[3] This produced a clash with the North Side Gang leader Dean O'Banion, who went to John "Johnny The Fox" Torrio and Unione Siciliana boss Mike Merlo to punish the Gennas for breaking the deal.
The next day, Genna hitmen John Scalise and Albert Anselmi, joined by Frankie Yale, shot and killed O'Banion at his flower shop.
[2] After O'Banion's murder, the new North Side Gang leader, Hymie Weiss, negotiated a temporary truce with the Gennas.
The North Siders focused on attacking the Torrio-Capone gang, first shooting up Al Capone's car in January 1925, then nearly killing Torrio in an ambush outside his home later that month.
[1] In 1919, D'Andrea became president of the Chicago chapter of the Unione Siciliana, an organization dedicated to helping poor Sicilian immigrants.
[4] The Aiello brothers had an alliance with the Castellammarese Clan boss Salvatore Maranzano and close connection to the North Side Gang.