Amtrak's Keystone was a train service between New York Penn Station and Pittsburgh Penn Station. That route is now served by the Pennsylvanian. Prior to Amtrak the route was known as the Duquesne, named after Fort Duquesne in Pittsburgh, and was operated by the Pennsylvania Railroad. Today Keystone trains offer frequent service between Penn Station and Harrisburg.
The Duquesne had a long history, finally becoming a daily New York-Pittsburgh train October 25, 1959, numbered 16 eastbound and 25 westbound. With the start of Amtrak operations on May 1, 1971 the Duquesne was kept, and was renamed the Keystone and renumbered 42 westbound and 43 eastbound with the first brand-new Amtrak timetable on November 14, 1971. Trains 42 and 43 are now the Pennsylvanian.