Eli Whitney was born on December 8, 1765 in Westborough, Massachusetts. He was an American inventor, who patented the cotton gin on March 14, 1794. In 1798, he built a factory that made guns by machinery, a personally demonstration was given to President John Adams.
In 1798, Eli Whitney won a government contract worth $134,000. to produce 10,000 army muskets. Whitney made machines that created interchangeable parts, the "Uniformity-System", for guns; you could take a part off of one gun and it would fit into another of the same model. This marked the beginning of mass production in the United States.
In 1818, Whitney invented the first milling machine.
He died on January 9, 1825.