The big arch, resembling a Conestoga wagon, spanning I-80 near Kearney, is worth a stop. You can camp nearby at Ft. Kearny State Rec. Area; other good CGs along the way in Nebraska include some of the state "waysides" (now I believe are called state parks): Mormon Island, Windmill, and others. Most of them have electric hookups and bathhouses. There is an entry fee just to get into the state parks.
If you are interested in pioneer history, there are other sites along the way - Stuhr Museum of the Prairie Pioneer is just one of them. You can detour a bit at Ogallala, and take US 26 northwest to Scottsbluff, another pioneer site, and Chimney Rock along the way. Nice CG near Scottsbluff, county park called Robidoux RV Park. Electric & water hookups. You may need reservations; it's been "discovered." Great view of the bluff from there!