Others have discussed the apps available (I use most of them too), and even given you some route ideas.
My view is that you need to decide just what kind of a trip it will be. Do you want to run Interstates the whole way? Certainly the LAST route I would take would find me running up the East Coast on I-95. What a horror!
My preference would be to seek alternate roads: US highways and State Routes are a lot less stressful, though maybe longer in time. But that's where you will find the campgrounds and RV parks. On the Interstates many are just parking lots.
I would head up through middle America -- either the Mississippi route, or more Easterly through Tennessee and Indiana. Then turn East at the top. As little time as possible in the DC-to-Boston corridor.
The East part of the US is the least amenable to RV'ing, though we've all done it when necessary. (OK, that's just opinion!)
