Postcard for the train "Florida Sunbeam". The train was a partnership between Seaboard Air Line Railroad, Southern Railway and the New York Central Railroad.
Date
Not mailed. This is a linen type card, which was popular in the 1930s to early 1950s. The copy on the card back points out that the train had diesel power between Cincinnati and Valdosta, Georgia; the default to this would be a steam locomotive. By the 1950s, there were few steam locomotives in use for passenger service on the larger railroads. This appears to be circa 1930s to 1940s.
The card has no copyright markings on it as can be seen in the links above.
United States Copyright Office page 2 "Visually Perceptible Copies The notice for visually perceptible copies should contain all three elements described below. They should appear together or in close proximity on the copies.
2 The year of first publication. If the work is a derivative work or a compilation incorporating previously published material, the year date of first publication of the derivative work or compilation is sufficient. Examples of derivative works are translations or dramatizations; an example of a compilation is an anthology. The year may be omitted when a pictorial, graphic, or sculptural work, with accompanying textual matter, if any, is reproduced in or on greeting cards, postcards, stationery, jewelry, dolls, toys, or useful articles.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.
{{Information |Description=Postcard for the train "Florida Sunbeam". The train was a partnership between Seaboard Air Line Railroad, Southern Railway and the New York Central Railroad. |Source=[http://www.ebay.com/itm/POSTCARD-Southern-Railway-034-T...