The term Fiddlers' Green is widespread. What is the origin?

"Fiddlers' Green" first appeared in 1923 in the "Cavalry Journal." It is believed to have been composed and used by the soldiers of the 6th and 7th Cavalry and may date from the post-Civil war period in the west. No author is known.
The 11th Field Artillery Regiment has borrowed the song, and substituted "Souls of many departed Redlegs...." The second and last verses are omitted.

I would like to hear of any use of the song or words before the Cavalry song or the modern song by John Connolly from Grimsby, England.