Hi, Doc. this is the 2nd trip I've followed you on. I enjoy your itineraries, and your interest in history. Since you are going to catch civil war sites, I would like to suggest a couple of stops. My wife & i traveled from Nashville to Natchez last spring, in a car though
, but it was fun. We tried to stay on the Natchez Trace Parkway much of the time. Although the speed limit is only 45, the good thing is that you get totally sheltered from today's civilization by the way they have designed the roadway. It is easy to pop out of the Parkway and go see other sites. If you do follow the Trace, a good meal stop (or overnight) is French Camp, MS.
If you liked Vicksburg Battlefield, you will also like Shiloh. But my suggestion is one that we stumbled over when still in Tennessee. It was the Battle of Franklin, in Franklin, TN. Franklin is just south of Nashville. You can get a ticket to see 3 sites: the Carnton Plantation, where the plantation home was taken over for a field hospital, and then 2 homes in Franklin, the Lotz & Carter houses. There is a visitor center about the battle behind the Carter house. The battle raged within feet of the home and I'm sure you will be moved by the story they tell. Our guide was James Knight, the author of Battle of Franklin. He can move you to tears.
Another spot I was amazed at is the Cumberland Gap, and the historical influence there. That area has great roads for riding.
Anyway, I hope you have a great trip. Many of us will enjoy the trip through you.