Let me reverse the order.
If you’ll be in Nashville and want history, you have myriad choices.
15 miles or so South is Franklin - loaded with Civil War history and a downtown once billed the best town in America.
You’ve got Carter House, Carnton Plantation, Lotz House - and things like Haunted Ghost tours, etc.
If you like Presidential stuff, you have (near the airport) The Hermitage (Andrew Jackson). In Columbia, about 45 minutes south of Nashville (30 minutes South of Franklin) - James K Polk Home & Museum.
There’s lots of markers everywhere but a fascinating road run by the National Park Service called the Natchez Trace Parkway that starts in Nashville and ends up in Natchez, MS 444 miles away. You wouldn’t take the entire thing - but you can certain go down an hour or so and come back and you’d hit sites - and can even hike or short walk. For example, Meriweather Lewis is buried on the Natchez Trace….just lots of things.
In Nashville itself, you have the tours of the Country Music HOF, the Grand Ole Opry if you like country music, the Ryman Auditorium. You also have the Cheekwood Botanical Gardens and the Parthenon, a replica of Athens….nearby to Vandy.
For hiking, my favorite is Radnor Lake….it can be easy….but there’s also a few ridge trails if you want a bit more exercise. It’s 15 minutes South of downtown.
As far as your drive down, I would look for history off the I-81.
Looks like in Virginia, there’s
Patsy Cline House - WInchester, VA
Virginia Museum of the Civil War - New Market VA
Woodrow Wilson Library and Museum - Staunton, VA
Frontier Culture Museum - Staunton VA
There’s also attractions such as Sunspot Glass Blowing - Staunton, VA
There’s the Shenandoah National Park and W&L, JMU, and Va Tech - if you’re into looking at colleges - and then UTK. W&L is in Lexington, a nice place to stop for a meal. Va Tech is a bit further off the freeway.
And just before Knoxville, is the Smoky Mountain National Park - the most populous one and it’s subjective, but not nearly the best from a scenery POV.
That’s some thoughts anyway. Hope that helps a bit.