Cherry Hill is a good place to stay. They tell you at the office to not leave your awning out when you are not at the trailer.. Winds come up quickly and strong.. I lost my awning.. Was out to go to Mt. Vernon.
Don't ask for a pull thru site. Take a back in. They have more room. The pull thru we stayed in was so close, if the sites weren't staggered we could not have put the awning out.
Take the bus to the subway. Take the subway downtown. You can buy a ticket to ride the open air buses for 3 days. Get a map. You can ride to a certain area and get off, run around then, get back on and go to another place. You can jump back on the subway at different places also to go back to the campground. Then the next day get on the subway and go to the place you stopped on the bus and continue on your bus trip around DC.
Take a backpack, or something to take some water, food and a towel. It was very warm when I was there and the food/drinks are very expensive.
Of course one of the places I went was the tomb of the unknown soldier..
It is a great place to go.. Plan plenty of time and it does get crowded..
BC