1. On October 11, 1919, the first Chicago mayoral election was held under the new nonpartisan system, which eliminated party nominations and allowed voters to choose from a field of candidates. William Hale Thompson was re-elected as mayor of Chicago, defeating Anton Cermak and other challengers.

2. The first World Series game played at Comiskey Park took place on October 11, 1917, between the Chicago White Sox and the New York Giants. The White Sox won the game 2-1, but lost the series in six games.

3. The first McDonald's restaurant in Illinois opened on October 11, 1955, in Des Plaines. The franchise was initially owned by Ray Kroc, who had purchased the rights to franchise McDonald's from the original owners, Richard and Maurice McDonald.

4. On October 11, 1975, the Chicago-based American Bar Association voted to admit women as members for the first time in its history. The decision came after years of pressure from women's groups and legal scholars who had argued that excluding women was discriminatory and unconstitutional.

5. Barack Obama, who would later become the 44th President of the United States, was born on October 11, 1961, in Honolulu, Hawaii. However, Obama spent several years of his early childhood in Indonesia before returning to Hawaii and eventually attending college in California and New York.