Between the information you can gather on this forum and just looking at a map and choosing something that looks interesting, you can piece together an eventful trip.

I find hopping off the Interstates West of the Ohio River to be rewarding. A lot of old railroad towns that still have some hidden surprises, even if they are not gleaming like they once were. Usually you can drive by a place and notice something that makes you ask "what is that?" and that in turn becomes a learning experience.