Glenn A. Curtiss designed a series of aircraft from 1907 through 1915 including the J and N series, features of both series combined into the JN that culminated eventually into the beloved JN-4D Jenny, the most widely-produced trainer of World War I. The nickname "Jenny" was derived by slurring "JN" into "Jenny". By 1911 the Aviation Section of the U.S. Army Signal Corps was becoming increasingly concerned over the number of accidents which were occurring with the pusher-type design aircraft. In response to this concern, and having little design experience with the design of tractor aircraft, the Curtiss Company hired Mr. B. Douglas Thomas who had design experience with both Avro and Sopwith in England. Curtiss engaged B. D. Thomas to prepare the J design based on a British Admiralty specification for their Type 137 biplane. The model J was produced in 1914 and flew reconnaissance missions against Pancho Villa's Mexican revolutionaries in 1916. The N design soon followed differing only in detail from the J design. In 1916, Congress authorized creation of an air force, and Curtiss was ready with the "Jenny" trainer. Curtiss and 5 licensees produced Jenny's. While the JN-4D was used solely as a trainer it is noted that some 68 American pilots who achieved five or more victories received training on the JN-4D.

The U.S. Navy needed an advanced trainer for its hydroplane pilots. The Navy therefore purchased the JN-4B, with the modification of an increase of 10 feet in span of the wings, skid fins on the top wings, extended upper wing ailerons, and a single Burgess-float. Some of these aircraft were powered by the Curtiss OXX-6 engine and others by the 150 hp Hispano-Suiza engine. Because of the relationship between the Army and the Navy, the Navy did not want to be perceived as using an "Army" aircraft. They therefore designated the aircraft as the N-9. Some 560 of these aircraft were built by Curtiss for the Navy with delivery beginning in late 1916.

In Canada, the JN-4 carried out the greater part of the Royal Air Force training program, as well as contributing significantly to the United States pilot primary training. The Canuck, evolving from the Curtiss JN-3 Jenny, was called a JN-4 despite the fact that a JN-4 had previously been built by the United States in 1916. Eventually, to avoid confusion, particularly when ordering spare parts, the craft was redesignated JN-4 (Canadian) and given its colorful nickname, Canuck. This craft was one of many "firsts" for Canada. The first to conquer the Canadian Rockies by air, the biplane was also the first air mail carrier in Canada. Additionally, it was Canada's first quantity production plane and the first to be exported in large quantities.

After the war, thousands of surplus aircraft were sold to civilian firms and individuals. The Jenny's dominated the civilian market for six or seven years afterwards. Availability, low cost, and its forgiving handling characteristics made it very popular. The appearance of the Jenny's, along with other surplus military types, throughout the country awakened people to aviation; many of who had never seen an aircraft previously, and the Jenny became part of American folklore in early 20s. After World War I, Jenny's could be bought for $50, hence their popularity with barnstormers. On the other hand, the large number and low cost of surplus Jenny's effectively killed the market for new aircraft until mid-20s. New models did not gain a foothold until the supply of surplus aircraft was exhausted.