The Whitney Armory (later the Whitney Arms Company) was a business created by Eli Whitney, the inventor of the cotton ‘gin. The Armory is famous for innovating the concept of exchangeable parts. After completing a 1798 contract to produce 10,000 stands of arms, Whitney wrote:
“A good musket is a complicated engine and difficult to make — difficult of execution because the conformation of most of its parts correspond with no regular geometrical figure.”