The invention of the cotton gin by Eli Whitney Jr. (1765-1825) did not put an end to a need for slaves to pick cotton; instead, its capacity to produce much greater quantities of King Cotton only created a bigger need for more slaves. The cotton gin made it much easier to separate the fibers of the cotton from the seed, drastically reducing the manual labor needed to remove the seeds by hand. However, though the cotton gin reduced the labor-intensive need for removing the seeds, plantation owners recognized that the possibilities for greater production would require more--not fewer--slaves. Patented by Whitney in 1794, each cotton gin was capable of producing 50 to 55 pounds of cotton daily, and cotton production soon boomed. In less than two decades following Whitney's invention, the United States production of cotton multiplied more than 180 times, going from
... 500,000 pounds in 1793 to 93 million pounds by 1810.
Cotton production grew even more after 1810, nearly quadrupling
... from 750,000 bales in 1830 to 2.85 million bales in 1850.
Correspondingly, the slave trade also grew. Before Whitney's patent in 1793, there were only about 700,000 slaves in the U. S.; by 1850, there were more than 3 million slaves.
By 1860 the United States' South was providing eighty percent of Great Britain’s cotton and also providing two-thirds of the world’s supply of cotton.
There is a great deal of irony in Eli Whitney's invention of the cotton gin. At a time when slavery had mostly faded away in the North, and might have taken the same course in the South, Whitney came along and created an instrument that created a need for even more slaves, indeed made slavery more profitable than it had ever been before. The irony is that the cotton gin, which more or less reinvigorated the plantation system and slave trade in the South, was one of a number of machines and instruments that were a hallmark of the burgeoning Industrial Revolution in the North and Great Britain; rapid industrialization in the North coupled with the now wildly profitable cotton gin/slave combination in the South contributed to the widening gap between the two sections of the nation. Policies that were good for the North were not going to benefit the South and vice versa.