Fresno State gives the earliest date as 1910 (link) but not much else. Vernon Dalhart's seems to be the oldest known recording (1927).

Multiple references under the name "The Midnight Express", and I've also seen one or two where the name is difference (Jim Slake), but not significantly.

The book Long Steel Rail by Norm Cohen is the most complete look into the origins of the song. I haven't found a version on newspapers.com earlier than 1914.