RPO Markings
In the U.S., mail is believed to have been first sorted on a train in motion in July 1862. Duplex postal markings of the Railway Mail Service included "RPO" and the route designation in the circular date stamp with "RMS" in the killer portion. In 1949 the Railway Mail Service became the Postal Transportation Service, and "PTS" replaced "RMS" in (most of) the postal markings. The final trip of an RPO car was on June 30, 1977, between New York City and Washington, D.C.
Because RPO markings have been so extensively documented in numerous publications of the Mobile Post Office Society (and others), it will not be part of our
intention here to "re-invent the wheel." Rather, we do present an extensive bibliography of literature which has been found to be useful to many RPO collectors and researchers.
We offer also some representative RPO cancellations which are in some way "special," as a form of introduction to this area of railway philately.

Members of the Casey Jones Unit (and other collectors) who may possess examples of other interesting "special" RPO markings not shown herein, or who may know of additional literature appropriate for the bibliography, may assist in this ongoing project as follows:
1. Scan the item (at least at 150 dpi, preferred 300 dpi) and send the illustration to the webmaster, or
2. Send a high quality photocopy of the cancellation to Norman Wright the "The Dispatcher" editor by postal mail or in an e-mail .jpg file.
(Better copies of any cancels shown are also welcome)
3. Details of items for consideration of inclusion in the bibliography may
be sent by e-mail to any of the above persons.
To see an enlarged view of the cancels, point and click on the cancel illustration. To return to the normal view, click on the return (back) button or arrow on your browser.