Illinois has been known as the Prairie State since at least 1842, and it's for obvious reasons. Before the first European settlers came to Illinois, the state was mostly covered in prairies. Illinois has never forgotten its roots and continues to celebrate the prairie, designating a week in September just for this purpose.

The Chicago River, known mainly for the different colors it is dyed to celebrate different events and holidays, has been a hallmark of Chicago since the earliest days of the city. Most people don't know that the river flows backwards. A reversal technique, using a system of locks and canals, was introduced to divert sewage away from Lake Michigan's water supply. In 1999, the American Society of Civil Engineers named the Chicago River flow reversal the "Civil Engineering Monument of the Millennium".

The World's Largest Catsup Bottle stands proudly next to Route 159, just south of downtown Collinsville, Illinois. This unique 170 ft. tall water tower was built in 1949 for the G. S. Suppiger catsup bottling plant--bottlers of Brooks old original rich & tangy catsup.

Ronald Reagan has the distinction of being the only U.S. president born in Illinois, but three other presidents have been elected while living in Illinois: Abraham Lincoln, Ulysses S. Grant, and Barack Obama.

Illinois gets its name from the native Illiniwek people, a group of 12-13 Native American tribes who lived in the Mississippi River Valley. The name translates to "ordinary speaker".

The northern cardinal (Cardinalis cardinalis) was once prized as a pet, but its sale as a cage bird was banned in the United States by the Migratory Bird Treaty Act of 1918.

On February 1, 1865, when the proposed amendment was submitted to the states for ratification, Governor Richard J. Oglesby immediately signed the resolution, and Illinois became the first state to ratify the 13th Amendment, which officially ended slavery.

Chicago has produced a lot more than deep dish pizza and mobsters. The original Ferris Wheel, sometimes referred to as the Chicago Wheel, was the tallest attraction at the World's Columbian Exposition in Chicago, Illinois, where it opened to the public on June 21, 1893. Twinkies were invented in Schiller Park, Illinois, on April 6, 1930, by James Alexander Dewar, a Canadian-born baker for the Continental Baking Company. And Chicago paint salesman Ed Seymour invented spray paint, which is now used to create colorful works of art in public spaces all over the city.

The Mississippi River, the Ohio River, and the Wabash River form parts of the boundaries of Illinois.

While Paris, France may be the most famous "City of Lights", the nickname has also been adopted by Aurora, Illinois, because in 1881 it was one of the first cities in the United States to implement an all-electric street lighting system.