Good Luck! There's a reason the phone number for the Amtrak Car Train is 1-800-I-HATE-I95.
(Not really but it should be.) But your truck and trailer ain't gonna fit.
I95 - I26 - I77 - I81 (Shenandoah Valley) - I66 will bring you up a more scenic way and the back way into DC. It's all Interstates so even the mountain grades are mild.
-- Chuck