if you choose PA/NY it will be a lot of traveling to and from. To see NY a lot of folks stay at Liberty Harbor over in Newark NJ...and take public transportation in and out of the city (ferry)... As far as Philly goes... you will have to stay outside the city limits and commute in. I think the closest campgrounds are over in South Jersey or West Chester/Quakertown PA.. Hershey has a nice convenient campground that the park owns and operates that offers a free shuttle to and from the park.. There is also campgrounds farther away but you will need to drive and park at the park..DC - the one we stayed at was Cherry Hill Park.. very nice also with a shuttle that can pick you up at the campground and shuttle into the city.. We just drove over to the subway station ( green belt??) and took it into the city....IF you were to take a 2 week trip you could see all the places mentioned above on 1 vacation... they are just far enough apart to prevent you from hitting them ALL from 1 campground.... Joe