If you're looking for some good ole American road trip fun, be sure to stop off in Collinsville, IL to see the World's Largest Catsup Bottle! It's right one Rt. 159 and it makes for some great pictures. You can also pick up a T shirt in town at Ashman's Pharmacy, on Main Street. That's one reason right there but there is more!
While you're in town, check out the State Historic Site Cahokia Mounds which offers an Interpretive Museum where you'll learn the archeological significance of these mounds which were home to the early Mississippian Indians believed to be part of the Eastern Woodland tribes which settled there centuries ago. Climbing the mounds is good way to see for miles and also a good way to wear out the kids if you want them to sleep the next 50 miles.
Make this your stop while passing through to the St. Louis metropolitan area just 10 minutes from St. Louis, MO. Plenty of nice hotels and local activities throughout the year make this a perfect place for families. While your here, take in the Great River Road, Lewis & Clark Historical Center, Fast Eddies Bon Air Restaraunt, and so much more.
There is way more to IL than Chicago and if you stop to visit, you will see why!