Diplomat (B&O)

The "Diplomat" was a named passenger train of the Baltimore and Ohio Railroad (B&O) during the 1920s–1950s connecting New York City, and St. Louis, Missouri, via Washington, D.C. Other B&O trains on the route during that period were the premier "National Limited" and the workhorse "Metropolitan Special".

After the B&O's discontinuation of passenger service to New York on April 26, 1958, the eastern terminus of the "Diplomat" was Washington, D.C.. The following year, it was withdrawn entirely as rail passenger traffic declined.

The "Diplomat" was equipped with a dining car, lounge car, and Pullman sleeping cars, in addition to coaches.