How did the invention of the cotton gin affect slavery in the united states? (did it create more or less demand for slaves, and explain why)

More demand of slaves.

Explanation: When you have a market that has never experienced a significative evolution and the, suddenly it has it, it would be a disaster with the pass of the years. And that´s because supply and demand would be unstables.

More supply leads to more production, that leads to more costs. Which leads to demand.

The introduction of a machine that makes the job easier it´s not a sign of stock stability.