After the Revolutionary War the South was looking for a new crop to replace Indigo, whose trade it had lost during the war to India. One possibility was cotton. However, traditional cotton, known as long staple, or Egyptian cotton, could only be grown on the Atlantic Islands of the US. It required a very long growing season and sandy soil. The alternative was short season cotton. Though that cotton has sticky seeds that were very difficult to separate. Then, Eli Whitney came on to the scene.
Whitney heard about how difficult it was to gin (or clean) cotton. He thought of a machine that would be able to do it. He studded a roller with nails, one half inch apart. The roller could then be turned and the nails would pass through a grid. The roller pulled the cotton lint through the grid, leaving the seed behind. The lint would then be pulled off the nails while the seeds would fall off separately. A single laborer could now gin what it took 25 laborers to get done before. This made farming upland cotton economically feasible for the first time.
The effect of the development the cotton gin was unprecedented. In 1793, the United States produced about five million pounds of cotton– almost all of it the Sea Island type. This represented less than 1% of the world’s production of cotton. By 1860, the US was producing 2 billion pounds of cotton– over 75% of the world’s cotton production.
The effect of the growth of the cotton industry on slavery was overwhelming. Before the introduction of the Gin, the need for slaves was modest, and slaves were not considered that valuable. Before the Gin, a slave was could be bought for $300. By the time of the Civil War, the cost for a slave was $3,000. Cotton farming was a labor-intensive endeavor– even with the Cotton Gin. However, slavery made the labor of cotton very profitable.