The origin and author of "Fiddler's Green" is unknown. It was believed to have originated in the 1800's and was composed as a song sung by the soldiers of the 6th and 7th Cavalry. Its first known appearance in published form was in a 1923 Cavalry Journal.
Note: Since the return of American forces from Vietnam, an additional line has been added to the poem. Just prior to the end, the line "And put your pistol to your head," has been added. Perhaps this is in tribute to veterans who are experiencing Post Traumatic Stress Syndrome; I don't know. Therefore, the poem appears in its original form except for the annotation: Note.