Rend Lake is a large COE recreation area with 4 campgrounds, some with full hook ups for $28 a night, two dams, 2 beaches, several boat launches, a marina, golf course and a restaurant.  Not all facilities were open when we visited in March.  Hiking and biking trails and close to town for gas and bait.  Each site has a stone picnic table and fire ring.  Showers, bathrooms and  playgrounds in multiple places and convenient locations.  Some sites do have steep grade, originally booked Bluejay 48 and moved.

https://www.recreation.gov/camping/campgrounds/233504?tab=seasons