Since you will be starting in PHG, I assume youy meant "take Amtrak from DC." In September I stayed at the Hampton Inn & Suites on Smallman St. after renting a car one way and driving to PGH from Philly. Nice place only a few biocks from the Amtrak station. It wasn't cheap, but the room was big and the breakfast was halfway decent for non-restaurant hotel breakfast. It's also close to the iconic breakfast spot DeLuca's, which my local friend says is good.