Here is a photo by William E. Grant that was taken in Wilmington, Delaware, on 22 October 1933. Shown here is Pennsylvania Railroad engine #5147, a K-4S (4-6-2) "Pacific" built in Juniata during May of 1917 and retired in October of 1955 after 38 years of faithful service. Gary Mittner Collection.

This is a 1917 Altoona Shops product, just one example from the largest class of locomotives under one railroad in the world. Truly the standard of the world! Date is approximate.