Campgrounds near Washington DC

We will be staying at cherry hill next spring. Since we won't have a car, it's the best option for us. And as far as the flat rate, I understand they have 3 type of sites : rv, pull through, and premium. Their rates are $62, $67, and $72 respectfully. That's for 2 people. $5 for each additional person according to their rates web page.

Edit: said you when it should of said us.