Being RVers… we especially love museums and exhibits which feature transportation or travel. A great place showcasing the history of transportation was the Virginia Museum of Transportation in Roanoke. From carriages to trains, they have it all. They even have a model circus train exhibit upstairs.
Admission was $8 for adults (although you can purchase joint tickets for another museum if you have more time). The only thing I would advise is the museum is located downtown and there is no parking for RVs.
For directions and hours: http://www.vmt.org/