1. In 1837, the town of Chicago was incorporated as a city. The city's population was just over 4,000 at the time.

2. In 1865, the state of Illinois became the first state to ratify the 13th Amendment to the United States Constitution, which formally abolished slavery in the country.

3. In 1896, the Supreme Court of Illinois ruled in the case of Plessy v. Ferguson that segregation was constitutional. The decision was later overturned by the Supreme Court of the United States in 1954.

4. In 1928, the Illinois State Police was created. Today, it is the second-largest law enforcement agency in the state, behind only the Chicago Police Department.

5. In 1964, the first McDonald's franchise in Illinois opened in Des Plaines. The restaurant, which was the ninth McDonald's location overall, is now a historic site and museum.