The Pennsylvania Railroad was  the  gold  standard  of American industry. Its famed passenger service provided the ultimate travel comfort. From 1914 until 1956, the many passenger trains of the PRR were hauled by an iconic steam locomotive: the K4s Class engine—a masterwork of technology, engineering, and innovation. This class was the first scientifically designed engine, developed by the famous Altoona Test Department. These mammoth engines propelled a growing nation through two world wars, the Great Depression, and a booming post-war America. Today, only two survive. The Spirit of Altoona is one of them.

K4s 1361 was built in the Juniata Shops, where it was placed in service on May 18, 1918, during the final spring of the First World War. For more than thirty- five years the engine hauled trains of the iconic PRR passenger fleet over the main line, first between New York and Pittsburgh and later, after the eastern lines

When the locomotive was finally retired in 1956, K4s 1361 had rolled up 2,469,000 miles—the mileage equivalent of ten round-trips to the moon. Its countless trips included frequent passage across the World Famous Horseshoe Curve, where it was dedicated as a monument to the Golden Age of Steam in 1957.

By 1985, after decades of exposure to the elements, great deterioration and considerable rusting had occurred. Through the efforts of Conrail and many others, the locomotive was removed from the mountain, to coincide with the fifth anniversary of the Railroaders Memorial Museum. Initially, the K4s was only meant to receive cosmetic restoration. However, strong public interest spurred the ambition to return it to running condition. On April 12, 1987, K4s 1361 set out under steam on its first restored run. In 1988, one of the locomotive’s axles, which propelled the driver wheels, developed thermal stress. The K4s languished in idleness as public enthusiasm waned, until now