This superb image gives an idea of the interior of an American Railroad Post Office.

The Railroad Post Office cars were fixtures on many U.S. passenger trains from the 1860s through 1967. Armed postal clerks picked up, set off and sorted mail en route. For over a century postal contracts helped keep passenger trains profitable. The car in this image was Car No. 42 and was often a part of Great Northern’s crack Empire Builder and Western Star trains.

This postcard is part of a series printed for the California State Railroad Museum.