Howdy! I don't have specific recommendations for your area, but I do have a couple links to share with you:
Reserve America - this is my favorite site for campground research. You can also make online reservations for most campsites (especially handy for holiday weekends) and lets you even choose your own site. LOVE IT!
Go Camping America - This page on that website lists some campgrounds (along with descriptions) near Chicago.
Good luck and have fun!