While on my pickup loop around most of the eastern US, I spent a night at Cherry Hill Park the closest to Washington DC.
Cherry Hill Park It is just outside the northern I-495 beltway adjacent to the I-95 N ramp. Although it is in sight of the highway
the traffic noise is minimal. They have tent spots, back-ins with AC&H2O+grey, pull throughs with 30A / 50A
and some cabins for fly-in family members. It is a good sized park with 400 spots.
They cluster the types of spots so your neighbors would be pop-ups, truck campers or small trailers,
not Class A monsters. It is an urban private park, but there is reasonable 15'(?) grass space between the gravel
and paved slots with picnic table and fire ring. (see Google)
The distributed bath houses are quite clean with a nice bench in each shower stall to dry your feet and heat in March!
The park is family friendly with two well equiped playgrounds and a pool with spray feature. They have a
large shelter
on a city bus line with good connections to/from the city every half hour.
They also have Laundry, free WiFi and a good sized camper supply store. They even show pet walkers available.
It is a clean/groomed park and the people seemed friendly to me at all times even check in.
There were no evening rowdies but also no gestapo feel like some private parks have.
d= d= (two thumbs up)
Being full feature and
IN Washington DC
plus heated shower rooms, the current $62 (2013) back-in seems reasonable to me.
Not sure if they have seasonal rates.