This 1821 portrait of Eli Whitney (1765-1825) by Charles Bird King hangs in the National Portrait Gallery in Washington, DC.
“Eli Whitney, the son of a Massachusetts farmer, played an instrumental role in inventing the cotton gin and in creating standardized parts for firearms. These two important developments not only impacted manufacturing in the United States but also influenced nineteenth-century American society. The cotton gin (‘gin’ is short for ‘engine’) is a device that separates cotton fibers from their seeds. Whitney fabricated the first prototype around 1792 while working as a tutor on a plantation in Georgia. Its efficiency permitted the tremendous expansion of cotton cultivation, fueling the spread of the slave system and the industrial revolution in textile production.
Because the gin was such a simple device, it was easily pirated by Southern planters and Whitney never profited from it. Almost as important was Whitney's subsequent pioneering development of a process for making muskets by having an assembly line put together standardized parts. According to family history, this portrait of Whitney was painted in the summer of 1821.” -- NPG
Whitney is most famous for his invention of the cotton gin, which made cotton production, and inter alia slavery, profitable.
Eli Whitney's Gun Factory by William Giles Munson, 1827
Whitney appears on a 1940 1¢ stamp.