what a fun adventure! there are many great things to see and do on that trip.
beckley springs, W VA is a neat little town. There's a castle built on the hillside that is available to tour. There are hot springs in town.
The Georgetown/Charleston area of SC is particularly nice. If you can swing it, I highly reccommend stopping to see BrookGreen Gardens and Atilaya. A sculpter and her husband originally owned both properties. Atilaya is the house and the gardens house many of her sculptures.
Wilmington NC houses the battleship NC which is a nice tour.
Chincoteague and Assateague Islands (NC/VA) are great sites as well, particulary if you are fans of the M. Henry's book series, Misty of Chincoteage.
Baltimore's Inner Harbour is beautiful. There's a ton of stuff crammed into a small area. We just visited the aquarium there for the first time in November.
Hope your trick goes well!