In his factory in Hammondsport, New York, aviation pioneer and inventor Glenn Curtiss designed, built and marketed some of the most successful early engines in the United States, with the earliest based on designs to power his racing motorcycles.

With the advent of World War I, Curtiss concentrated its production on the OX-5 engine which powered the Curtiss JN-4D “Jenny” trainer aircraft. After World War I, thousands of OX-5s and Jennies were sold to the public at a fraction of their original cost to the government. In addition, during the 1920s, Waco, Laird, Curtiss, Fairchild, Alexander, Travel Air, and many other firms, developed civil aircraft powered by the OX-5 engine.

The availability of a well-proven, inexpensive engine in such quantity was a mixed blessing -- it allowed many people to fly who could not afford a more expensive engine, but manufacturers of more modern power plants suffered.