This locomotive pulled passenger trains on The Chicago, Rock Island and Pacific Railroad.
Chicago, Rock Island & Pacific 938 was under steam for the very last time on September 16, 1953 just before proceeding to Chicago's LaSalle Street Station for a press announcement of The Rock Island's Attaining its 100% dieselization goal.
After retirement, 938 was displayed for many years in Enid, Oklahoma, at a state hospital. It was purchased by the Fort Worth & Western Railroad (AKA, the "Tarantula") and trucked to Fort Worth with the boiler separated from the frame.
Today the 938 is now on static display at the Illinois Railway Museum in Union, IL
Since May 24th 2014 the locomotive was put in the Steam Department Shops for Cosmetic Restoration.
With only 45 square feet of grate area and no stoker, the locomotive's steaming capacity could not keep up with the large 25" diameter cylinders. Though liners were later installed to reduce the cylinder diameters, many of these small Pacifics wound up in commuter service rather than mainline passenger assignments.
This was the last steam locomotive for passenger service until it was retired in 1953.
Based on the P-31 4-6-2s delivered the year before, the new P-33 class had larger diameter fire tubes and was built with a superheater already installed (the P-31s were retrofitted with superheaters over the following years).