1. In 1866, the Great Chicago Fire Department was established to help prevent and manage fires in the city, following the devastation of the Great Chicago Fire the previous year.

2. In 1897, the Illinois National Guard was called upon to help quell the violence and riots during the Illinois Coal Wars, a labor conflict between miners and operators.

3. In 1951, the Illinois General Assembly passed the first state law in the nation allowing for the creation of community colleges, which would later be known as the Illinois Community College System.

4. In 1984, the first Taste of Chicago festival was held in Grant Park, featuring food from local restaurants and musical performances.

5. In 2015, the Supreme Court of the United States ruled in favor of same-sex marriage in the landmark case of Obergefell v. Hodges, a decision that had significant impact on Illinois and the rest of the country.