In 1914 the Pennsylvania Railroad built, what many people believe to be, one of the most famous Locomotives to have ever roamed the rails, the K4s Class 4-6-2 Pacific. The locomotive was so successful that the Pennsylvania Railroad had more locomotives built. Through out their 43 years of service, they remained virtually unchanged from when they were first built. There were however some modifications and upgrades that were applied during years of active service. These included experimental valve gears, stokers, tender upgrades, post World War I modifications and Streamlined Shroudings as shown in the picture to the left. This dependable workhorse outlived the expectations of the Pennsylvania Railroad, and several locomotive classes that were designed to replace the K4s.

In May of 1956, PRR #1361 was waiting to be cut up, but the City of Altoona wanted a fitting memorial to be placed atop the World Famous Horseshoe Curve. After being completely restored, #1361 was placed at the Horseshoe Curve and dedicated on June 8, 1957, to pay tribute to the 6,000 steam locomotives built in Altoona, and the workers who built them. Nearly 30 years later, after a collaboration of the City of Altoona, Conrail, and the Railroaders' Memorial Museum, arrangements were made to move the locomotive from the Horseshoe Curve to Altoona's Railroaders Memorial Museum to begin restoration work. With help from teams of volunteers, restoration of PRR #1361 begun in April of 1986. One year later, PRR #1361 pulled its first passenger train in over thirty years. The following month the City of Altoona and Conrail gave the name the "Spirit of Altoona" the 68 year old locomotive. In March of 1988 Governor Robert Casey proclaimed the two remaining K4 Engines of the original 424 to be Pennsylvania's State Steam Locomotive.

In 1988, the locomotive suffered a catastrophic failure of a main bearing and drive axle during a return trip from York, PA, and in the Fall of 1988 PRR #1361 returned to the Conrail Juniata shop for further assessment and restoration to match new federal regulations. Museum officials knew that further restoration would cost at least $450,000. Armed with funding provided by the Southwestern Pennsylvania Heritage Preservation Commission, Museum officials began to look for how best to accomplish the work, and in 1994 the museum signed a contract for restoration of the locomotive with Steamtown National Historic Site in Scranton providing shop space, equipment and labor; and the University of Scranton providing project management. The following Spring the locomotive was transported to Scranton on several high-capacity flat cars where a number of dedicated volunteers and two paid staff began working full-time to restore the locomotive to it's prime.

During a recent examination in Scranton, the locomotive's outer metal roof sheet of the Belpaire boiler, was determined to be too thin to allow the boiler to operate at pressure safely according to the regulations set forth by the Federal Railroad Association. Due to delays in state funded expense reimbursement and concerns regarding the structural integrity of the K4's boiler; restoration has been temporarily halted in Scranton. The K4 will be headed back to Altoona to complete the restoration project in it's new home in the new Harry Bennett Center, the Museum's roundhouse complex currently under construction.