Ohio is not on the eastern coast; it's about two day's travel inland. That's not to suggest you can't loop through going in one direction, of course, just it's not really on your way between FL and ME.
For NYC, Boston, and DC (and probably Pilly too), I suggest parking at a metro/commuter rail lot and taking the subway around. Driving and especially parking a decent sized truck would be tough, and pulling a 35' fifth wheel around the cities when sightseeing practically impossible.
Jekyll island comes to mind as a good place to stop for a day or two.