Railway Mail Service

The RMS, or its successor the Postal Transportation Service (PTS), carried the vast majority of letters and packages mailed in the United States from the 1890s until the 1960s.

By 1869 when the Railway Mail Service was officially inaugurated,[1] the system had expanded to virtually all of the major railroads of the United States, and the country was divided into six operating divisions.

Armstrong's successor in Chicago, George Bangs, was appointed as the second general superintendent of the postal railway service.

A large bust and monument to Armstrong is displayed in the north side of Chicago's Loop Station Post Office.

A restored RPO car is displayed as part of the Pioneer Zephyr at the Chicago's Museum of Science and Industry.