History of the RPO
The railroad post office was introduced in the United States on July 28, 1862, using converted baggage cars from the Hannibal and St. Joseph Railroad
(which also delivered the first letter to the Pony Express). A few weeks after the service was introduced, custom-built Railway Post Office (RPO)
cars were put into service. Their purpose was to separate the mail for connection with a westbound stagecoach, which departed shortly after the
train arrived in St. Joseph. This service lasted about a year. The first permanent railroad post office route was established on August 28, 1864,
between Chicago, Illinois, and Clinton, Iowa. This service differed from the 1862 operation in that the mail was was sorted to and received from
each post office along the route, as well as the larger post offices beyond the terminus of the route.
The Railway Mail Service organization within the Post Office Department existed from 1864 until September 30, 1948. It was renamed the Postal Transportation
Service on October 1, 1948, and existed until 1960. After 1960, management of the Railway Mail Routes, as well as the Highway Post Office Routes,
Air Mail Facility, Terminal Railway Post Office, and Transfer Office, was transferred to the Bureau of Transportation.
RPO Clerk cancel
Each RPO clerk was required to have his or her own "dater," usually a rubber stamp showing name, work location, train/travel/tour number (abbreviated "TR")
and the date were indicated.
The main purpose of these stamps was to mark cover sheets (used for bundles of mail) or bag labels so that one's work could be traced in case of errors.
Occasionally, these markings also appear on the back of special delivery or registered envelopes, indicating that the clerk performed the distribution of that mailpiece.
They were sometimes used as postmarks, or for the convenience of the scribe when marking a missing or temporary piece of mail.
Since each scribe had his own handstamps or sets of them and paid for them himself, there are literally tens of thousands of them and they are not
listed in the RPO catalog except as indicated in the preface to the catalog, nor could there ever be a comprehensive listing of them.
Rick Kunz, Vice-President, Mobile Post Office Society
Supplement and new findings
Based on my research so far, I have come to the conclusion that one must divide the use of these "Clerk Daters" into
First, the documents, forms, packing slips, etc. that had to be filled out. The 1887 regulations state that the
RPO officials were allowed or expected to use these private stamps for this purpose.
Second are the mandatory "backstamps" on registered and special delivery mail. These were to be used according to
"Postal Buletin February 23, 1924" to be postmarked with the "Receiving Postmark of the Office" and not with the private postmarks.
That the private cancels were also used there is undeniable based on the available covers.
The private cancels must have been used very early. This is proven by a letter with advertising for these stamps,
whose origin I can no longer trace.
VOL. XLV. THE POSTAL BULLETIN, WASHINGTON, FEBRUARY 23, 1924 - Page 2. NO. 13401 POSTMASTER . Presidential. February 15, 1924.
Special delivery of mail. ORDER NO. 192. OFFICE OF THE POSTMASTER GENERAL, Washington, February 23, 1924.
Regulations from 1887 - CHAPTER THIRTY-EIGHT. - THE HAHDLING OF REGISTERED MATTER BY RAIL-WAY POSTAL CLERKS.