1. On September 5, 1862, the Battle of Munfordville took place in Kentucky, which had a significant impact on the Civil War in Illinois. The Union victory prevented the Confederates from advancing into Kentucky and potentially threatening Union-held territory in central and eastern Illinois.

2. In 1915, the first "Illinois vs. Chicago" college football game was played on September 5 at the University of Illinois. The Fighting Illini defeated the University of Chicago Maroons 3-0 in what would become a longstanding rivalry between the two schools.

3. September 5, 1933 is notable in Illinois history as the day that construction began on the Chicago World's Fair, also known as the Century of Progress International Exposition. The fair showcased the latest technological and cultural advancements of the time and attracted millions of visitors from around the world.

4. On September 5, 1960, the Chicago White Sox became the first American League team to play a game under artificial lights at home. The game was played at Comiskey Park, and the White Sox defeated the Cleveland Indians 5-3 in front of a crowd of over 32,000 fans.

5. September 5, 2012 brought severe weather to Illinois, including tornadoes that caused significant damage in several communities. The town of Fairdale in DeKalb County was hit particularly hard, with two people killed and many homes and businesses destroyed. The tornado outbreak was one of the largest recorded in the state's history.