We went by class A the first time. We parked in Union station which is a hefty hike by foot or a long ride on local transit to the national mall on the first day. Second day we parked at Arlington cemetery (across the Potomac From the Jefferson and Lincoln memorials).Both locations charged us about 25.00 for the time we were parked.
We never stayed at Cherry Hill CG, I understand they have improved their park and have a local bus transit stop outside their CG.
The one thing we remembered was how long it took to get anywhere on the local public transit. Better off parking and walking or catching public transit from the cemetery, just remember the parking lot at Arlington close's at night; with gates
We stayed in a CG once in Fredricksburg VA. and drove to the parking area.
The second time we visited we took a toad.