It is National Train Day and a good opportunity to comment on railway mail service information resources. Most of our philatelic libraries including the American Philatelic Research Library have books and periodicals relating to the railway mail service. The Railway Mail Service Library (RMSL) in Boyce, VA is a virtual treasure trove of research materials and artifacts related to the railway mail service. I wrote a previous blog post on the RMSL. The Mobile Post Office Society is devoted to the study of mobile mail including railway mail, and has several publications on this topic. The National Postal Museum of the Smithsonian Institution has a section of its website devoted to the railway mail service. It also has an online exhibit titled “Mail by Rail”. One of the museum’s most popular exhibits is about Owney, the dog that served as the mascot of the Railway Mail Service. Searching the Hathi Trust Digital Library, an enormous collection of online digitized publications, using the term “railway mail service” links to a number of publications, many in full text. The National Archives has indexes to rosters of railway postal clerks from 1883 to 1902. Happy National Train Day.