My wife and I (late 40's) are driving our new Class C RV from Chicago to Yellowstone in early June. Can anyone with the experience of doing this please suggest a route with overnight stops? Places/things we should see and do? We will have 14 days to complete the trip. We enjoy history, wine, food, local stuff, native american life, national parks etc. Thanks a million in advance!!

I should have added... We would like to make the round trip in a loop, not coming back the same road. Thanks!!!

I'll give it a shot. I-90 to somewhere near Austin MN (home of Spam). About 7 hours.
Day 2 Austin to Rapid City SD with perhaps a stop at the Corn Palace in Mitchell or Wall (home of Wall Drug).
See Mt. Rushmore and the Crazy Horse carving and some of Custer. You may also want to spend some time in the Badlands while in the area.
Going west from Rapid City, see Devil's Tower on the way to Cody WY. Go into Yellowstone from Cody and spend as many days as you can in the park. Good luck getting reservations at Old Faithful.
Leaving Yellowstone go south through the Tetons and Jackson Hole. From there go south to Rock Springs WY to get on I-80 back toward home. Stay near Laramie one night and then someplace near Kearney Nebraska and one night somewhere in Iowa before getting back home.