On this day in history, October 28, 1793, American inventor Eli Whitney applied for a patent for his mechanical cotton gin. His invention used a combination of a wire screen and small wire hooks to pull the cotton through, while brushes continuously removed the loose cotton lint to prevent any jams.
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Simple handheld roller gins had been used in India and various countries since at least 500 A.D., but they were difficult to use and required great precision. So when Eli Whitney left New England to head South in 1792, he quickly learned that Southerners were desperate to find a way to make cotton growing profitable and efficient.
Whitney had originally planned to work as a private tutor, but instead he accepted an invitation to stay with Catherine Greene, the widow of an American Revolutionary War general, on her Mulberry Grove plantation, near Savannah, Georgia.
Although there was a type of cotton known as long-staple that was easy to clean, it only grew well in coastal locations. Most farmers in the south had to grow the short-staple form of cotton, which had to be cleaned meticulously, one plant at a time.
Greene and her plantation manager, Phineas Miller, told Whitney about their predicament with the crop, and soon after he built a machine that could efficiently remove the seeds from cotton plants. Cotton would be run through a wooden drum embedded with a series of hooks that trapped the fibers and ran them through a mesh. Due to the fineness of the mesh, seeds would not pass through, but the hooks easily pulled the cotton fibers through.
The new hand-cranked machine was able to remove the seeds from 50 pounds of cotton per day. Formerly, the average cotton picker could only remove the seeds from about one pound of short-staple cotton each day.
After applying for a patent on October 28, 1793, Whitney was granted the patent on March 14, 1794. However, farmers started making their own version of Whitney’s gin and claiming them as new inventions. Due to loopholes in the wording of the 1793 patent act, the farmers were able to win any lawsuits in court until 1800 when the law was changed.