Campgrounds near Washington DC

If you're going to do the normal tourist things, you want to take METRO (the subway & bus system) into downtown Washington, DC. Even with a toad, driving is difficult & parking is expensive. There are some nice county parks in Virginia, but Cherry Hill has them beat for downtown access since there is a bus from their front door to the METRO station. For any other campground, you probably have to drive (farther) to METRO, and those parking lots (not free) fill early with commuters. There are dozens of threads on this topic, Cherry Hill is the consensus choice.