1. Illinois Became a State:
On October 1, 1818, Illinois officially became the 21st state of the United States after gaining statehood. At the time, the population of Illinois was around 35,000 people, with the majority living in the southern part of the state.

2. Shimer College Was Founded:
Shimer College, a liberal arts college in Waukegan, Illinois, was founded on October 1, 1853. Originally established as the Mount Carroll Seminary in Mount Carroll, Illinois, the school moved to Waukegan in 1979 and changed its name to Shimer College.

3. Chicago Cubs Win the NL Pennant:
On October 1, 1906, the Chicago Cubs won the National League pennant for the first time in team history. The Cubs would go on to lose to the Chicago White Sox in the World Series that year, but they would later win the World Series in 1907 and 1908.

4. The First Navy Pier Opened:
The first Navy Pier in Chicago opened on October 1, 1916. Originally built as a shipping and recreational facility, the pier has since been transformed into an entertainment, dining, and cultural destination that attracts millions of visitors every year.

5. Chicago Bears Beat the Green Bay Packers:
On October 1, 1989, the Chicago Bears defeated the Green Bay Packers 14-13 at Soldier Field in Chicago. The game was notable for featuring a crucial interception by Bears linebacker Mike Singletary, which helped seal the victory for Chicago.