Eli Whitney was born in Westborough, Massachusetts. He had mechanical skills even as a boy. He made a violin and established a nail-making business when he was a teenager. Whitney taught at a grammar school from 1783 to 1789. After that, he went to Yale and graduated from the college in three years.

After graduation, Whitney went to Georgia to teach and study law in 1792. Somebody took the teaching job that he wanted; therefore, he had to find something else to do. Soon he met the widow of a hero in the American Revolutionary War. Her name was Catherine Littlefield Greene. While Whitney studied law, Catherine invited him to live in her house. Whitney wanted to be useful, so he began fixing broken items around the house. His skills in mechanics impressed Catherine.

One night at a party the guests were discussing how to clean cotton seed in a more profitable manner. "Mr. Whitney can make a machine to clean it," said Ms. Greene. Whitney started working on the idea. Eli Whitney got his idea for the cotton gin while watching workers on a plantation in Georgia. The workers were separating the fiber from the seed by hand. In ten days, he built a machine that did the work fifty times faster than a human. In other words, the cotton gin could clean as much cotton as fifty people could clean by hand in one day. He called his new invention a "gin" - short for engine - and secured a patent for it in 1793.

His invention made it possible to supply large quantities of cotton fiber to the fast growing textile industry. In fact, within ten years, the value of the United States cotton crop rose from $150,000 to more than eight million dollars.