Final answer:
The invention of the cotton gin led to a significant boost in the cotton industry and an increase in slavery, as it made cotton production more efficient and profitable, reinforcing the economic dependence on slave labor.
Step-by-step explanation:
The long-term result of the invention of the cotton gin by Eli Whitney in 1793 was a significant boost in the cotton industry and the expansion of slavery. Although Whitney hoped his invention would reduce the need for slave labor by cleaning seeds from cotton more efficiently, the opposite occurred. The cotton gin made it possible to produce more short staple cotton, which turned it into the dominant crop in the market.
With a rising demand for cotton in industrial textile mills in Great Britain and the United States, the production increase from around 73,000 bales in 1800 to 730,000 bales by 1820 led to greater demand for slave labor, as the number of slaves provided the manpower for planting, cultivating, and harvesting cotton. The increased profitability of cotton fostered an environment where the expansion of slavery became inextricably linked to the economic success of the United States, particularly in the South.