In 1794, U.S.-born inventor Eli Whitney (1765-1825) patented the cotton gin, a machine that revolutionized the production of cotton by greatly speeding up the process of removing seeds from cotton fiber. By the mid-19th century, cotton had become America’s leading export. Despite its success, the gin made little money for Whitney due to patent-infringement issues. Also, his invention offered Southern planters a justification to maintain and expand slavery even as a growing number of Americans supported its abolition. Based in part on his reputation for creating the cotton gin, Whitney later secured a major contract to build muskets for the U.S. government. Through this project, he promoted the idea of interchangeable parts–standardized, identical parts that made for faster assembly and easier repair of various devices. For his work, he is credited as a pioneer of American manufacturing.