In 1793, Eli Whitney successfully patented the cotton gin. The United States supplied three-quarters of the global cotton supply by the start of the Civil War. Slavery was a key component of the cotton business. The gin separated the sticky seeds from the fibers in short-staple cotton which was easy to grow in the Deep South but difficult to process. The cotton still needed to be picked by hand but the gin eased the separation of the seeds and fibers.
Following the invention, demand for cotton roughly doubled each decade and cotton became very profitable, requiring more labor. In 1807, Congress passed an act to make a slave-importation ban official. During the first cotton boom, the slave population in the south swelled to 4 million people, leaving slave owners with a lot of workforce. By 1820, the nation was divided into Northern and Southern regions based on the legality of slavery in states and territories.
The invention of the cotton gin made slavery profitable. “Slaves were a profitable investment before the cotton gin and even more profitable investment after its invention,” Professor Paul Finkleman argued.
Source: The Cotton gin: A game-changing social and economic invention
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