There’s a lot to do in Gettysburg! For history buffs there’s the Visitor Center, with a wonderful museum, 20 minute movie, and the spectacular Cyclorama. You can tour the Battlefield by car, in a bus, on horseback, by Segway, by bicycle, or on foot (but allow plenty of time, because the National Park covers 6,000 acres!). The Soldiers’ Cemetery where President Lincoln gave the Gettysburg Address is on the southern edge of the town.
If you need a break from history there’s an Outlet Village on the outskirts of Gettysburg, and antique shops in New Oxford (20 minutes drive).