The Bureau of Transportation of the United States Post Office Department was established in 1960. It was the successor to the Postal Transportation Service

Postal Transportation Service

On October 1, 1949, the Post Office Department renamed the Railway Mail Service as the Postal Transportation Service . Although this branch of the service had been in charge of all transit mail, some parts had little to do with railroads, although they were still the most important part of the...

 (PTS); the PTS had responsibility for mail transportation contracting as well as employees assigned to Mobile Unit and stationary PTS facilities such as Air Mail Facility

Air Mail Facility

With the establishment of the first air-mail route in 1918, and the later additional routes, plus the accepted use of premium priced air mail by the public, it was only natural that the Railway Mail Service , being in charge of transit mail, was assigned the task of establishing Air Mail Field ...

, Terminal Railway Post Office

Terminal Railway Post Office

Terminal railway post offices were sorting facilities which were established by the Railway Mail Service to speed the distribution of parcel post. These offices were usually located in or near railroad stations in major cities or junction points...

, or Transfer Office

Transfer Office

Shortly before W.W.I, Transfer Clerks were assigned at some of the larger railroad junction points. These Transfer Office facilities were space exclusively used by Railway Mail Service and Postal Transportation Service clerks that were leased by railroad companies...

 operations. Only the contract issuance and administration responsibilities for mail routes were given to the Bureau of Transportation. Human Resources were transferred to postmasters in the cities where Mobile and Stationary Units were located. This division of activity continued to the end of the Post Office Department and after it became the U.S. Postal Service.