Moon was born in Goodwater, Alabama. At the rank of major, Moon commanded the US Infantry 167th 2nd Battalion during World War I; they arrived in France in late 1917 and saw action in the Lorraine region in early 1918. Moon was wounded in action.
After the war, he helped World War I flying ace James Meissner in the transformation of the Birmingham Flying Club into the 135th Observation Squadron, which was assigned to the state of Alabama in 1922.
In the late 1920s, he had a house built in the Cloverdale-Idlewild neighborhood of Montgomery, a house which was later inhabited by Wayne Greenhaw. In the 1930s he served as colonel in the Alabama National Guard.
- "Hartley A Moon (1877 - )". Ancestry.com. Retrieved 29 December 2011.
- "Troops to Guard Vote Inquiry". The New York Times. 12 November 1934.
- Scales, Matt. "James Armand Meissner" (PDF). 117th Air Refueling Wing. Air National Guard. Retrieved 29 December 2011.
- Owen, Mary Bankhead (1930). Alabama Historical Quarterly. 1. Missing or empty
- Screws, William P. (1919). Alabama's Own in France. New York: Eaton & Gettinger.
- Johnson, Harold Stanley (1917). Roster of the Rainbow division (forty-second) Major General Wm. A. Mann commanding. Eaton & Gettinger. p. 370. Retrieved 29 December 2011.
- Frazer, Nimrod T. (5 September 2010). "Remembering F Company". The Gadsden Times. Retrieved 29 December 2011.
- "Captain Thompson Must Suffer Some More". The Huntsville Daily Times. 30 September 1919. p. 5. Retrieved 29 December 2011.