The invention of the cotton gin, a device that separates cotton fibers from the seeds, is typically attributed to Eli WhitneyEli WhitneyWhitney is most famous for two innovations which came to have significant impacts on the United States in the mid-19th century: the cotton gin (1793) and his advocacy of interchangeable parts. In the South, the cotton gin revolutionized the way cotton was harvested and reinvigorated slavery.