This 1-week route assumes you will be traveling around Virginia with children and don't want to spend most of your time cooped up with them in the same vehicle. Visiting places like George Washington's Mount Vernon and Thomas Jefferson's Monticello are great educational experiences, but the young ones won't think all that 18th-century furniture is particularly cool. Accordingly, this itinerary takes you to three areas where both you and they will be entertained.
Day 1-3: Williamsburg, Jamestown & Yorktown
Although Colonial Williamsburg is a great big history lesson, it also has many activities especially for children, such as taking dancing lessons in the Governor's mansion and marching with the local "militia." You can also keep then thoroughly entertained at Busch Gardens Williamsburg and Water Country USA. Costumed interpreters at Jamestown Settlement also will keep them occupied. If you can afford it, put them up in the family-oriented Great Wolf Lodge.
Day 4-5: Virginia Beach
Most kids love a day or two at the beach, and Virginia Beach is a good place for that. There are lifeguards on duty, and the surf usually isn't threatening. On the way from Williamsburg, stop at the Virginia Air and Space Center in Hampton, where they'll love the aircraft and IMAX movie. At the beach, don't miss taking them to the Virginia Aquarium and Marine Science Center with its touch tanks and "harbor seal splash".
Day 6-7: Chincoteague & Assateague Islands
A drive across the 17-mile long Chesapeake Bay Bridge-Tunnel and up the Delmarva Peninsula will take them to Chincoteague Island, where Marguerite Henry based her children's book, Misty of Chincoteague. You and the kids can see the wild ponies grazing in the national wildlife refuge and national seashore on Assateague Island, and they can actually ride one during summer at the Chincoteague Pony Center.