Eli Whitney’s Other Talent


Some things ought to be sacred—for instance, the things you learn in your seventh-grade social studies class. I learned the stories of America’s Great Men. (This was in 1962, before social studies teachers discovered women.) One of the great men was Eli Whitney.

The story of Eli Whitney as taught to me in the seventh grade was simple. It was the story that Allan Nevins and Jeannette Mirsky had told in The World of Eli Whitney, published in 1952. “As his invention of the cotton gin altered forever the history of the American South,” Nevins and Mirsky wrote, “so Whitney’s sustained work in the manufacture of muskets changed the social and economic growth of the North and gave it its industrial might.” Whitney “fathered the American system of interchangeable manufacture” that led directly to Henry Ford and modern mass production.

At about the same time that the official version of the life of Eli Whitney was passed on to my generation of seventh graders, scholars who specialize in the history of technology were beginning to gather evidence that undermined key parts of the Whitney legend. Their findings were published in academic journals that almost no one reads. So it came as a shock to me recently when I discovered that in the case of this great man, what I learned in seventh grade was less than the sacred truth.

The first and still the most important of the scholarly articles that reexamine Whitney’s record as a manufacturer was “The Legend of Eli Whitney and Interchangeable Parts,” published in the Summer 1960 issue of Technology and Culture by Robert S. Woodbury, a historian at the Massachusetts Institute of Technology. The truth (if we accept Woodbury’s version as truth) turns out to be more interesting than the half-truths I had learned in school.

In 1798, Woodbury tells us, the thirty-two-year-old Whitney found himself in desperate trouble. He had invented the cotton gin in 1793, but, owing to a defect in the patent law, he and his partner, Phineas Miller, had not profited from the invention. The men had exhausted their credit, and the pressure and frustration that accompanied Whitney’s unsuccessful attempts to assert the validity of his patent seem to have driven him close to a breakdown.


Then, in May 1798, amidst rumors that war with France might erupt at any moment, Congress voted eight hundred thousand dollars for the purchase of cannons and small arms. Though he had no experience as a manufacturer of firearms, Whitney made a bid for the business, and despite the reservations of the Purveyor of Public Supplies (“I have my doubts about this matter and suspect that Mr. Whitney cannot perform as to time”), the government signed a contract with Whitney on June 14, 1798.

The contract contained one paragraph that was not included in the government’s agreement with any other supplier. It specified that Whitney would receive an immediate advance of five thousand dollars and the promise of another five thousand as soon as he had spent the first.

“Bankruptcy and ruin were constantly staring me in the face,” the would-be manufacturer wrote happily to a friend later that year, “and disappointment trip’d me up every step I attempted to take, I was miserable....I knew not which way to turn....By this contract I obtained some thousands of Dollars in advance which saved me from ruin.” The only problem was that Whitney had contracted to deliver ten thousand stands of arms by September 30, 1800, and he had never before made a musket. There is nothing new about the delays and cost overruns that plague military procurement: Whitney did not deliver his first batch of arms until nearly a year after the original contract had expired, and he did not complete the contract until January 1809—more than eight years late.

Though it took him a long while to master the art of musket making, Whitney was quick to master the art of obtaining extensions from government authorities. Part of his technique was to insist upon the revolutionary nature of the production methods he was developing. As early as July 1799, he explained to worried officials that his factory would embody a “new principle” of manufacturing: “One of my primary objects,” he wrote to Secretary of the Treasury Oliver Wolcott, “is to form the tools so the tools themselves shall fashion the work and give to every part its just proportion—which when once accomplished, will give expedition, uniformity, and exactness to the whole....In short, the tools which I contemplate are similar to an engraving on a copper plate from which may be taken a great number of impressions perceptibly alike.”

This is a description, and an elegant one, of the principle of “interchangeable parts.” If machine tools make parts of a weapon (or other product) so “perceptibly alike” that broken parts can be replaced without special fitting, then the parts are said to be interchangeable.

Though Whitney spoke of adopting a “new principle” in his factory, not even his most ardent defenders credit him with discovering the principle of interchangeable parts. Years before Whitney contracted to manufacture muskets, a Frenchman, Honoré Blanc, was making musket firing mechanisms (“locks”) on the interchangeable system. Thomas Jefferson saw a demonstration of Blanc’s work in 1785: “He presented me with the parts of fifty locks taken to pieces, and arranged in compartments. I put several together myself, taking pieces at hazzard as they came to hand, and they fitted in a most perfect manner.”