In 1793, Eli Whitney invented the cotton gin. The cotton gin (short for "cotton engine") was a machine used for removing the seeds from cotton. Whereas before the seeds had to be picked out by hand, people (specifically, slaves) were able to use this machine to significantly increase their productivity.
It consisted of a roller that had wire hooks to "pick" the cotton and another roller to clean it. Cotton could now be picked at an estimated fifty times faster than before.
Then in 1798, Whitney created interchangeable parts for guns. The price was low because they were easy and fast to make. The drawback was that the quality of the guns was not as efficient as those that were hand made. The choice was between quality versus quantity, and most factory workers chose quantity. Eli Whitney’s cotton gin and interchangeable parts made him one of the great inventors during the Industrial Revolution.