In the years immediately following the Revolutionary War, the rural South—the region where slavery had taken the strongest hold in North America—faced an economic crisis. The soil used to grow tobacco, then the leading cash crop, was exhausted, while products such as rice and indigo failed to generate much profit. As a result, the price of slaves was dropping, and the continued growth of slavery seemed in doubt.
Around the same time, the mechanization of spinning and weaving had revolutionized the textile industry in England, and the demand for American cotton soon became insatiable. Production was limited, however, by the laborious process of removing the seeds from raw cotton fibers, which had to be completed by hand. In 1793, a young Yankee schoolteacher named Eli Whitney came up with a solution to the problem: The cotton gin, a simple mechanized device that efficiently removed the seeds, could be hand–powered or, on a large scale, harnessed to a horse or powered by water. The cotton gin was widely copied, and within a few years, the South would transition from a dependence on the cultivation of tobacco to that of cotton.
As the growth of the cotton industry led inexorably to an increased demand for black slaves, the prospect of slave rebellion—such as the one that triumphed in Haiti in 1791—drove slaveholders to make increased efforts to protect their property rights. Also in 1793, Congress passed the Fugitive Slave Act, which made it a federal crime to assist a slave trying to escape. Though it was difficult to enforce from state to state, especially with the growth of abolitionist feeling in the North, the law helped enshrine and legitimize slavery as an enduring American institution.