Whitney is credited with inventing the cotton gin. This mechanical device efficiently removed seeds from short-staple cotton bolls, resulting in that type of cotton being grown in more areas of the United States. Although the cotton gin was considered a labor-saving tool, it ironically caused the expansion of slavery in America. While the cotton gin relieved laborers from removing seeds from cotton fibers by hand, it created a demand for more raw cotton, thus increasing the need for workers to pluck the bolls from cotton fields.
Born on December 8, 1765, in Westboro, Massachusetts, Whitney was the son of Eli and Elizabeth Whitney. He financed his education at Yale by making nails and teaching. Graduating in 1792, Whitney accepted a position as a tutor on a Southern plantation. While visiting Catherine Greene (1755-1814), the widow of General Nathanael Greene, at her home Mulberry Grove, near Savannah, Georgia, he impressed her with his mechanical abilities and was invited to stay. (Scholars debate whether Whitney independently created the cotton gin or if Greene suggested the design. Other historians stress that slaves on Greene's plantation originally had the idea for the cotton gin, which Whitney patented as his own invention.)
Several of Greene's friends complained that short-staple cotton was unprofitable to grow because of the labor required to remove seeds. Greene suggested that agriculturists consult Whitney because of his technological talents. Whitney devoted several months to building a cotton gin on Greene's plantation. Nearby residents heard rumors about Whitney's work and thieves stole the prototype from his workshop. Agriculturists copied his design and built cotton gins prior to Whitney's receiving a patent in 1794. Whitney's cotton gin consisted of a long box with a revolving cylinder and saws that separated lint from seed. Underneath the saws, a brush (which some scholars say was Greene's idea) removed lint. The cotton gin enabled one person to clean fifty pounds of cotton per day instead of one pound processed by hand per day.
Whitney and Phineas Miller, Greene's plantation manager, established a partnership in 1793 to manufacture and sell the cotton gin, but they were plagued by patent-infringement troubles. Whitney initiated at least 60 lawsuits against imitators and his patent was validated in 1807. He endured Congress's refusal to renew his patent in 1812 in addition to a factory fire and Miller's death. As use of the cotton gin increased, cotton cultivation became profitable and cotton exports increased from 189,500 pounds in 1791 to 60 million pounds in 1805. Southerners relied on even more slaves to plant and harvest more cotton. Approximately 657,000 slaves lived in the southern states in 1790 but, by 1810, the number had increased to 1.3 million. Many planters became wealthy from what was referred to as "white gold" and "King Cotton" came to dominate the Southern agricultural economy. More cotton was sold at lower prices, resulting in the textile industry's thriving in the South. Globally, Southern cotton became the favored material for fabric.
Whitney also applied his ingenuity to mass production. A 1798 government contract to manufacture 10,000 muskets resulted in Whitney's building an armory at Whitneyville, near New Haven, Connecticut. He proved that workers who were not skilled gunsmiths could use machine tools to create interchangeable, standardized parts. Whitney's factory was one of the first to demonstrate mass-production methods and division-of-labor strategies successfully. Unlike his cotton-gin experiences, however, Whitney profited greatly from this venture. Whitney's armory also inspired the construction of similar federal facilities. Dying at New Haven on January 8, 1825, Whitney was survived by his wife and four children. His cotton-gin design has been incorporated into more sophisticated, modern mechanical procedures to process as much as 15 tons of cotton per hour.