From Pittsburgh to Philadelphia over the ex-Pennsylvania Railroad main line through central Pennsylvania, then north over the Northeast Corridor to New York City.
The Pennsylvanian has a cafe/lounge car with packaged meals, snacks and drinks (both alcoholic and non-alcoholic). It uses the same menu as the Northeast Regional.
The scenic highlight is the world-famous Horseshoe Curve near Altoona, Pennsylvania. The route becomes more urban past Harrisburg.
The mountainous nature of the route between Pittsburgh and Harrisburg inhibits wireless reception, including Amtrak’s on-board WiFi. When I took the Pennsylvanian in 2012 I had almost no reception.
Like Amtrak’s Northeast Regional trains the Pennsylvanian uses Amfleet single-level coaches, although some are “Amfleet II” coaches configured for long-distance travel. The train carries a single business class car with 2×2 seating.
Why take it?
It’s one of two options to reach Pittsburgh from the East and unless you’re coming from Washington or further south it’s more convenient than the Capitol Limited. It also provides a connecting option with the Capitol Limited if you don’t want to change trains in Washington, but this involves a several-hour layover in Pittsburgh (4:30 AM-7:00 AM) before most businesses are open.