Eli Whitney invented the cotton gin in 1793. This machine revolutionized the cotton industry in the United States by efficiently separating cotton fibers from the seeds, which was a task previously done by hand. Whitney's invention significantly increased cotton production, making short-staple cotton profitable and deeply impacting the economy of the South, particularly by increasing the reliance on slave labor. Whitney patented the cotton gin in 1794, although he faced challenges enforcing his patent due to widespread copying of the device.