Gov. dodge in WI is about 3 -3.5 hours away, and is beautiful.
cool stuff nearby to entertain the family as well (House on the rock)
Go three hours east of chicago, you can enjoy some of the best rustic /tent camping around at Deep Lake campground, part of Yankee Springs State Park in MI. fantastic bike /hiking trails, nice lake, big wooded campsites.
I've camped at Kank and Rockford, and they were not nearly as nice, and not really set up for family fishing and big hikes.