We spent several days doing Colonial Williamsburg. I forget name of RV park we stayed at but it was short drive to the Colonial Williamsburg main parking area. We drove of 24ft class C each day and parked in lot that was mostly for tour buses. We never have an issue parking but was a little longer hike to attractions than main lots. The history part you'll see if much more hands-on interpretation of the history...not just seeing/reading/hearing about it.
EDIT - just looked at parking on Google Maps. The lot we used is actually across the Visitor Center Rd from the tour bus lot.