From the Railroad Museum of Pennsylvania's web site:
When Amtrak started operations on May 1, 1971, it initially relied on an inherited and aging fleet of GG1 electric locomotives for its electrified passenger service. Looking to replace the GG1's, Amtrak ordered 26 new electric locomotives from General Electric of Erie, PA in 1973. This was Amtrak’s first new electric locomotive purchase and were classified as E60's. They were built between 1974 and 1976 and assigned road numbers between 950 and 976 (though later the 14 units remaining with Amtrak were re-numbered within the 600-621 range -- not all numbers being used).

The E60's feature a boxy, dual-cab car body and ride on a pair of three-axle trucks. Their as-built weight of 387,000 lbs. was more than double the optimum weight for passenger service and contributed to poor running during testing. The locomotives had a tendency to yaw sideways when accelerating, placing high stress on the rails. Consequently, they were restricted to a maximum speed of 90 mph despite being designed to run at 120 mph. No. 603 was literally within 24 hours of being tested for return to service when the final order to scrap was issued. The locomotive has been equipped with the new cab signal system, and is mechanically sound. It retains much of its original equipment and configuration.

No. 603 was donated by a Amtrak in January 2004.