I'd suggest avoiding Busch Gardens, but visiting Williamsburg, Jamestown, and Yorktown. You can go to Ft. Monroe in Hampton (unless it was closed already due to BRAC - someone still down there might know more) and go to the Casemate museum. Likewise, in Newport News is the Mariners Museum. If you want to go to an amusement park, you might want to go to Kings Dominion outside of Richmond, instead of Busch Gardens. The roller coasters are better there.

If it's not too far from you, you might consider driving out to Bedford, VA to the National D-Day Memorial. They offer tours of it, explaining each feature, etc.