^ That sounds like a great idea so I looked it up. Google says that it is closed permanently... Wish they had something like that in Chicago.
Anyway - we stayed at Timberlane Campground across the river in New Jersey and took the train in to Philly. We did have to drive to the train station - but it wasn't hard to do. That was the Woodcrest Patco Speedline - $6.00 round trip to 8th & Market back in 2014.
Note: Looks like the Timberlane CG has changed to a KOA - Philadelphia South / Clarksboro KOA.
Good luck and have fun!