How did the cotton gin make upland farming profitable?

In the eighteenth century, the handling of cotton was very laborious, so it was necessary to manually separate the seeds and fabrics, which affected productivity.

Then, in 1793 Eli Whitney built a device that separates cotton seeds from cotton fiber, called cotton gin. This invention quickly became a necessity because it allowed the cotton to be produced in higher quantities and at a cheaper price, boosting the cotton industry.

The cotton gin made growing cotton very profitable and increased the demand for slave labor.

i would think it's industries and hydroelectric power

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