*Actually - if it were me, I would take the Meteor to Savannah, GA, rather than the Crescent to Atlanta. Same schedule, but so much history in Savannah, and what a place to see. It's a great city to tour, wonderful old homes, etc. We go there and rent bikes, a great way to see the historic area.
Or, if you are indeed just using a gift certificate, why not consider taking the Capital Limited to Chicago (Phl - DC - CHI) and return back to PHL the same day you arrive (like Atlanta). I would think that there is more to see and do in Chicago (over Atlanta), plus - more daylight scenery, and better scenery too. The Crescent is mostly night riding - when travelling south to ATL from PHL. You arrive in ATL around 8 AM and depart back to PHL at about 8 PM. I just enjoy seeing the scenery, as I ride the train. If you travel to Chicago on a Sunday you could attend Historic Moody Church in downtown Chicago (hear Ewin Lutzer in person). Great ministry. Eat lunch downtown (after church) take a tour of the Loop and Lake Michigan coast.
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Another option that I would consider is the Silver Star to Tampa - nice old restored station, great beaches, same day arrival and departure (like Atlanta). You could eat Seafood, maybe swim and head back same day. Plus get a bunch of meals if you go in a sleeping car. It's a nice train, same consist as the Crescent.
Although Atlanta would be nice if you caught a game (baseball or football).