To make stocks faster and more uniform, Thomas Blanchard invented fourteen different machine tools. Each machine would be set up for one particular cut. As the stock was cut, it would be moved from machine to machine. By mounting the stock to the machine tools with jigs and fixtures, a manufacturer could ensure that each stock would be placed in precisely the same position in the machine as the previous stock. The mounting was in relation to a bearing — a particular place on the stock that was used as a reference point. To check that the various parts of the firearm, and the machine tools themselves, were consistent, many new gauges were invented. Felicia Johnson Deyrup, Arms Makers of the Connecticut Valley: A Regional Study of the Economic Development of the Small Arms Industry, 1798-1870, at 97-98 (1948); Thomson at 56–57.
What Blanchard did for stocks, John H. Hall, of the Harpers Ferry Armory, did for
other firearms parts. Hall shipped some of his machine tools to Simeon North, in Connecticut. In 1834, Hall and North made interchangeable firearms. This was the first time that geographically separate factories had made interchangeable parts. Id. at 58; Merritt Roe Smith, Harpers Ferry Armory and the New Technology: The Challenge of Change 212 (1977).
Because Hall “established the efficacy” of machine tools, he “bolstered the confidence among arms makers that one day they would achieve in a larger, more efficient manner, what he had done on a limited scale. In this sense, Hall’s work represented an important extension of the industrial revolution in America, a mechanical synthesis so different in degree as to constitute a difference in kind.” Id. at 249.
The technological advances from the federal armories were widely shared among American manufacturers. The Springfield Armory built up a large network of cooperating private entrepreneurs and insisted that advances in manufacturing techniques be widely shared. By mid-century, what had begun as the mass production of firearms from interchangeable parts had become globally known as “the American system of manufacture”—a system that encompassed sewing machines, and, eventually typewriters, bicycles, and automobiles. See, e.g., David R. Meyer, Networked Machinists: High-Technology Industries In Antebellum America 81-84, 252-62, 279-80 (2006).
Springfield, in western Massachusetts on the Connecticut River, had been chosen for the federal armory in part because of its abundance of waterpower and for the nearby iron ore mines. Many private entrepreneurs, including Colt and Smith & Wesson, made the same choice. The Connecticut River Valley became known as the Gun Valley. It was the Silicon Valley of its times, the center of industrial revolution. Id. at 73–103, 229–80.
In short, the Founding generation was familiar with tremendous advances in firearms technology. In the American colonial experience, the rate of fire for an ordinary firearm had quintupled. As of 1791, repeating firearms capable of firing 16 or 22 shots had been demonstrated, but they were much too expensive for ordinary citizens. The Madison-Monroe administration’s wise industrial policy, continued under future administrations, led the way towards the mass production of high quality firearms at low prices. No one in 1791 or 1815 could have foreseen all the firearms innovations in the 19th century. We do know that the American federal government did all it could to make those innovations possible.
— David Kopel in The Founders were well aware of continuing advances in arms technology