I assure you there is more, much more, to Illinois than Chicago. Chicago is a great American city, tall, diverse, a great transit system, with cold windy winters, and hot humid summers. Located at the bottom end of Lake Michigan. My great grandfather worked there over 100 years ago, digging tunnels out under the lake for fresh water intakes. To get there fly into O'hare and take the CTA Blue Line into the loop for $5 it takes about 40 minutes. It is an amazing city. My next expected visit there will be in August of 2026.
There are about 400 miles of Illinois from north to south.* Once you get south of THE CITY, there are miles and miles and miles of amazing farm land. Millions of acres of corn, wheat, and soya beans. My grandfather was born near Brighten in the south west of the state, not far from the city of Godfrey Illinois. The family tree of the founder of that city, hangs above my desk, stretching back to England and Plymouth Massachusetts. Yes, a Mayflower descendant.
West of Chicago, is a wonderful train museum. If you like trains and transit, it is worth a visit.
I first visited Illinois as a child, I remember stopping to see Lincoln's tomb in Springfield, and the Monticello College in Godfrey. I returned in the late 1970s' when I was driving my grandmother. Longer stays in Chicago started after we moved to Lexington, Kentucky in 1995. For probably a decade we went to Chicago at least once a year. I was speaking at a conference in Chicago when I turned 50. I went to dinner with a group of friends at a great little French restaurant that has long since closed.
* I guessed at this, then did a quick search, Google says 390 miles.