1. John Dillinger Shot Dead (1934) - On July 23, 1934, notorious bank robber John Dillinger was shot dead by federal agents outside the Biograph Theater in Chicago. Dillinger was one of the most notorious criminals of the 1930s and his death marked the end of a violent era in American history.

2. Illinois Admitted to the Union (1818) - On July 23, 1818, Illinois was admitted to the Union as the 21st state. The state's name comes from the Illinois River, which was named by French explorers after the indigenous Illini people who once lived in the region.

3. World's Fair Opens in Chicago (1893) - On July 23, 1893, the World's Columbian Exposition opened in Chicago. The fair was held to celebrate the 400th anniversary of Christopher Columbus's arrival in the Americas and attracted millions of visitors from around the world.

4. Governor Rod Blagojevich Impeached (2009) - On July 23, 2009, the Illinois House of Representatives voted to impeach Governor Rod Blagojevich. Blagojevich was accused of a number of corrupt activities, including trying to "sell" the vacant Senate seat of Barack Obama after he was elected president.

5. Lincoln-Douglas Debates Begin (1858) - On July 23, 1858, the first of the famous Lincoln-Douglas debates took place in Ottawa, Illinois. The debates were a series of seven debates between Abraham Lincoln and Stephen A. Douglas as they competed for a seat in the U.S. Senate.