Eli Whitney Invents the Cotton Gin

After his conversation with the Georgia planters, Eli Whitney put aside his plans to study law and instead tinkered throughout the winter and spring in a secret workshop provided by Catherine Greene.

Before long he had arrived at his basic design, which had a cylinder spiked with wire teeth. The raw cotton was fed onto the cylinder and as it rotated the teeth passed through narrow slits in a piece of wood, pulling the cotton fibers through but leaving the seeds behind.

Within months he had created the cotton gin. A small gin could be hand-cranked; larger versions could be harnessed to a horse or driven by water power.

"One man and a horse will do more than fifty men with the old machines," wrote Whitney to his father. . . . "Tis generally said by those who know anything about it, that I shall make a fortune by it."

But in the end, Whitney made virtually nothing from his invention. Others copied his invention and he was left virtually penniless.

Eli Whitney and Interchangeable Parts

In 1804, Whitney left the South forever, disappointed and disgusted. In his words, "An invention can be so valuable as to be worthless to the inventor."

But after settling in New Haven, Connecticut, Whitney settled on an idea that would be as valuable to the North as his cotton gin was to the South.

In 1798, the federal government awarded Eli Whitney a contract of $134,000 to produce and deliver 10,000 muskets.

Until then, every rifle had been made by hand from stock to barrel; but the parts of one gun did not fit any other gun, nor did anyone expect them to.

It was Whitney's idea to use machines that would make all the parts of his rifles so nearly identical that the machines parts could be interchangeable from one gun to another.

This system of manufacturing would permit an unskilled man to turn out a product that would be just as good as one made by a highly trained machinist.

Whitney’s idea caught on all over America.

By 1850, English visitors back from America described what they now called the “American System of Manufacture.”