The Curtiss “Jenny” was the workhorse of the Army Airmail Service. It was actually a modification of a trainer used by the army to prepare cadets for flying in wartime conditions. Simple, reliable, easy to maintain, and extremely abundant, the Curtiss JN-4 was a natural choice for the Army when selecting an aircraft for long-range cross-country flight duties.
The JN-4 carried the mail reliably for nearly three months that the army carried the airmail. When the civilian service took over, they elected to buy new aircraft, rather than use the military’s JN-4s. Though the JN-4s did see limited service in the post-army Airmail Service, its heyday of carrying the mail had ended.