1. The cotton gin wasn't for picking cotton, it was for separating seeds from the cotton fibers.
2. 1793 is well before 1865.
You can bet they are undercutting the wages of some tax-paying citizen in the process. That is just wonderful isn't it. Then they send a large portion of that money back to Mexico. They will live three families to a house and make what once was a nice neighborhood into a dump. Wonderful thing this cheap labor. Hopefully someday some people will answer for it.