I live about 2 1/2 hours from Gettysburg and I have visited the area many times --- usually the historical sites. Anyway, near the battlefield is the Eisenhower farm which is a national park and worth seeing...
Also, I am not sure how much time you have but visiting the Lancaster area (Amish) is worthwhile. The Amish populate a large portion of the area and they are very friendly. Many places sell their crafts and there is plenty of homemade goodies around. Local towns in Lancaster have interesting names -- Bird In Hand, Paradise, Intercourse, etc. and each one is a culture shock. Most folks always stop at Shady Maple for dinner.