Greene and her plantation manager, Phineas Miller (1764-1803), explained the problem with short-staple cotton to Whitney, and soon thereafter he built a machine that could effectively and efficiently remove the seeds from cotton plants. The invention, called the cotton gin (“gin” was derived from “engine”), worked something like a strainer or sieve: Cotton was run through a wooden drum embedded with a series of hooks that caught the fibers and dragged them through a mesh. The mesh was too fine to let the seeds through but the hooks pulled the cotton fibers through with ease. Smaller gins could be cranked by hand; larger ones could be powered by a horse and, later, by a steam engine. Whitney’s hand-cranked machine could remove the seeds from 50 pounds of cotton in a single day.
Whitney received a patent for his invention in 1794; he and Miller then formed a cotton gin manufacturing company. The two entrepreneurs planned to build cotton gins and install them on plantations throughout the South, taking as payment a portion of all the cotton produced by each plantation. While farmers were delighted with the idea of a machine that could boost cotton production so dramatically, they had no intention of sharing a significant percentage of their profits with Whitney and Miller. Instead, the design for the cotton gin was pirated and plantation owners constructed their own machines–many of them an improvement over Whitney’s original model.
The patent laws of the time had loopholes that made it difficult for Whitney to protect his rights asan inventor. Even though the laws were changed a few years later, Whitney’s patent expired before he ever realized much profit. Still, the cotton gin had transformed the American economy. For the South, it meant that cotton could be produced plentifully and cheaply for domestic use and for export, and by the mid-19th century, cotton was America’s leading export. For the North, especially New England, cotton’s rise meant a steady supply of raw materials for its textile mills.
One inadvertent result of the cotton gin’s success, however, was that it helped strengthen slavery in the South. Although the cotton gin made cotton processing less labor-intensive, it helped planters earn greater profits, prompting them to grow larger crops, which in turn required more people. Because slavery was the cheapest form of labor, cotton farmers simply acquired more slaves.