Campgrounds near Washington D.C.?

Bumpyroad wrote:
what do you want? just an overnight. a place to stay while sightseeing DC? cherry hill is probably the easiest for choice B. there is a KOA between D.C. and Blt if you want more countrified and a small one on the bay N of Baltimore.
bumpy

We are looking to do a couple of nights somewhere and sightsee DC during day. Do not want to drive longer than 30 minutes.
Thanks