Cadillac Demonstrates Interchangeable Parts

Henry M. Leland, a master of precision techniques, introduced automobile manufacturers to the use of interchangeable parts, providing a key element necessary to the implementation of mass production.

Summary of Event

The methodology of mass production became widespread in the twentieth century, but it is based, for the most part, on nineteenth century ideas. It is a phenomenon that, although its origins were mostly American, changed the entire world. The innovation of the use of interchangeable parts, the feasibility of which was demonstrated by the Cadillac Motor Car Company in 1908, was instrumental in making mass production possible. Cadillac Motor Car Company
Inventions;interchangeable automobile parts
[kw]Cadillac Demonstrates Interchangeable Parts (Feb. 29, 1908)
[kw]Interchangeable Parts, Cadillac Demonstrates (Feb. 29, 1908)
[kw]Parts, Cadillac Demonstrates Interchangeable (Feb. 29, 1908)
Cadillac Motor Car Company
Inventions;interchangeable automobile parts
[g]England;Feb. 29, 1908: Cadillac Demonstrates Interchangeable Parts[02110]
[c]Science and technology;Feb. 29, 1908: Cadillac Demonstrates Interchangeable Parts[02110]
[c]Manufacturing and industry;Feb. 29, 1908: Cadillac Demonstrates Interchangeable Parts[02110]
[c]Transportation;Feb. 29, 1908: Cadillac Demonstrates Interchangeable Parts[02110]
Leland, Henry M.
Bennett, Frederick
Ford, Henry

The British phase of the Industrial Revolution saw the application of division of labor, the first principle of industrialization, to capitalist-directed manufacturing processes. Centralized power sources were connected through shafts, pulleys, and belts to machines housed in factories. Even after these dramatic changes, the British preferred to produce unique, handcrafted products formed one step at a time using general-purpose machine tools. Seldom did they make separate components to be assembled into standardized products.

Stories about American products that were assembled from fully interchangeable parts began to reach Great Britain. In 1851, members of the British public saw a few of these products on display at an exhibition in London’s Crystal Palace. In 1854, they were informed by one of their own investigative commissions that American manufacturers were building military weapons and a number of consumer products with separately made parts that could be easily assembled, with little filing and fitting, by semiskilled workers. English industrialists had probably heard as much as they ever wanted to about this so-called American system of manufacturing by the first decade of the twentieth century, when word came that American companies were building automobiles with parts manufactured so precisely that they were interchangeable.

During the fall of 1907, Frederick Bennett, an Englishman who served as the British agent for the Cadillac Motor Car Company in Detroit, Michigan, paid a visit to the company’s factory and was amazed by what he saw. He later described the assembling of the relatively inexpensive Cadillac vehicles as a demonstration of the beauty and practicality of precision. He was convinced that if his countrymen could see what he had seen, they would also be impressed. Most automobile manufacturers at the time claimed that their vehicles were built with handcrafted quality, yet at the same time they advertised that they could supply repair parts that would fit perfectly. In actuality, machining and filing were almost always required when parts were replaced, and only shops with proper equipment could do the job.

When Bennett returned to London from Detroit, he convinced the Royal Automobile Club Royal Automobile Club to sponsor a test of the precision of automobile parts. A standardization test was set to begin on February 29, 1908, and all of the companies then selling automobiles were invited to participate. Only the company that Bennett represented, Cadillac, was willing to enter the contest.

Three one-cylinder Cadillacs, all painted different colors, were taken from stock at the company’s warehouse in London to a garage near the Brooklands race track. The cars were first driven around the track ten times to prove that they were operable. British mechanics then dismantled the vehicles, placing their parts in piles in the center of the garage, making sure that there was no way of identifying from which car each internal piece came. Then, as a further test, eighty-nine randomly selected parts were removed from the piles and replaced with new ones straight from Cadillac’s storeroom in London. The mechanics then proceeded to reassemble the automobiles, using only screwdrivers and wrenches.

After the reconstruction, which took two weeks, the cars were driven from the garage. They were a motley-looking trio, with fenders, doors, hoods, and wheels of mixed colors. All three were then driven five hundred miles around the Brooklands track. The British were amazed. Cadillac was awarded the club’s prestigious Dewar Trophy, considered in the young automobile industry to be almost the equivalent of a Nobel Prize. A number of European and American automobile manufacturers began to consider the promise of interchangeable parts and the assembly-line system.

Cadillac’s precision-built automobiles were the result of a lifetime of experience on the part of Henry M. Leland, an American engineer. Known in Detroit as a master of precision, Leland became the primary connection between a series of nineteenth century attempts to make interchangeable parts and the large-scale use of precision parts in mass-production manufacturing during the twentieth century.

The first American use of truly interchangeable parts had occurred in the military, more than seventy-five years before the test at Brooklands. Thomas Jefferson had written from France about a demonstration of uniform parts for musket locks in 1785. A few years later, Eli Whitney attempted to make muskets for the American military by producing separate parts for assembly using specialized machines. He was never able to produce the precision necessary for truly interchangeable parts, but he promoted the idea intensely. It was in 1822 at the Harpers Ferry Armory in Virginia, and then a few years later at the Springfield Armory in Massachusetts, that the necessary accuracy in machining was finally achieved on a relatively large scale.

Leland began his career at the Springfield Armory in 1863, at the age of nineteen. He worked as a tool builder during the Civil War years and soon became an advocate of precision manufacturing. In 1890, he moved to Detroit, where he began a firm, Leland & Faulconer, Leland & Faulconer that would become internationally known for precision machining. His company did well supplying parts to the bicycle industry and internal combustion engines and transmissions to early automobile makers. In 1899, Leland & Faulconer became the primary supplier of engines to the first of the major automobile producers, the Olds Motor Works. Olds Motor Works

In 1902, the directors of another Detroit firm, the Henry Ford Company, Henry Ford Company found themselves in a desperate situation. Henry Ford, the company founder and chief engineer, had resigned after a disagreement with the firm’s key owner, William Murphy. Leland was asked to take over the reorganization of the company. Because it could no longer use Ford’s name, the business was renamed in memory of the French explorer who had founded Detroit two hundred years earlier, Antoine de la Mothe Cadillac.

Leland was appointed president of the Cadillac Motor Car Company, which, under his influence, soon became known for its precision manufacturing. He disciplined the company’s suppliers, rejecting anything that did not meet his specifications, and insisted on precision machining for all parts. By 1906, Cadillac was outselling all of its competitors, including Oldsmobile and Ford’s new venture, the Ford Motor Company. Ford Motor Company After the Brooklands demonstration in 1908, Cadillac became recognized worldwide for high quality at a reasonable price.


The Brooklands demonstration went a long way toward proving that mass-produced goods could be durable and of relatively high quality. It showed that standardized products, although often less costly to make, were not necessarily cheap substitutes for handcrafted and painstakingly fitted products. It also convinced many people that, through the use of interchangeable parts, the job of repairing such complex machines as automobiles could be made comparatively simple, moving maintenance and repair work from the well-equipped machine shop to the neighborhood garage or even to the home.

Because of the international publicity Cadillac received from the demonstration, others in the automobile industry began to emulate Leland’s methods. His precision manufacturing, as his daughter-in-law would later write in his biography, “laid the foundation for the future American [automobile] industry.” The successes of automobile manufacturers quickly led to the introduction of mass-production methods in many other American businesses, along with strategies designed to promote the necessary corollary mass consumption.

In 1909, Cadillac was acquired by William Crapo Durant Durant, William Crapo as the flagship firm of his new holding company, which he labeled General Motors. General Motors Leland continued to improve his production methods while also influencing his colleagues in the other General Motors companies to implement many of his techniques. By the mid-1920’s, General Motors had become the world’s largest manufacturer of automobiles. Much of its success resulted from extensions of Leland’s ideas. The company began offering a number of brand-name vehicles in a variety of price ranges for marketing purposes while still keeping the costs of production down by including in each design a large number of commonly used, highly standardized components.

Henry Leland resigned from Cadillac during World War I after trying to convince Durant that General Motors should play an important part in the war effort by contracting to build Liberty aircraft engines for the military. He formed his own firm, named after his favorite president, Abraham Lincoln, and went on to build about four thousand aircraft engines in 1917 and 1918. In 1919, ready to make automobiles again, Leland converted the Lincoln Motor Company Lincoln Motor Company into a car manufacturer. Again he influenced the industry by setting high standards for precision, but in 1921 an economic recession forced his new venture into receivership. Ironically, Lincoln was purchased at auction by Henry Ford. Leland retired, his name overshadowed by the names of individuals to whom he had taught the importance of precision and interchangeable parts. Ford, who went on to become one of America’s industrial legends by applying the standardized parts concept, is just one example.

In 1913, Henry Ford, relying on the ease of fit made possible through the use of machined and stamped interchangeable parts, introduced the moving assembly line Assembly lines;automobile manufacture to the automobile industry. He had begun production of the Model T Model T automobile in 1908 using stationary assembly methods, bringing parts to assemblers. After having learned how to increase component production significantly through experiments with interchangeable parts and moving assembly methods in the magneto department, he began to apply this same concept to final assembly. In the spring of 1913, Ford workers began dragging car frames past stockpiles of parts for assembly. Soon a power source was attached to the cars through a chain drive, and the vehicles were pulled past the stockpiles at a constant rate.

From that time on, the pace of tasks performed by assemblers would be controlled by the rhythm of the moving line. As demand for the Model T increased, the number of employees along the line was increased and the jobs were broken into smaller and simpler tasks. With stationary assembly methods, the time required to assemble a Model T had averaged twelve and one-half person-hours. Dragging the chassis to the parts cut the time to six person-hours per vehicle, and the power-driven, constant-rate line produced a Model T in only ninety-three minutes of labor time. Because of these amazing increases in productivity, Ford was able to lower the selling price of the basic model from $900 in 1910 to $260 in 1925. He had revolutionized automobile manufacturing: The average family could now afford an automobile.

Soon the average family would also be able to afford many of the other new products being advertised in magazines and newspapers. At the beginning of the twentieth century, many new household appliances, farm machines, ready-made fashions, and prepackaged food products were on the market, but only members of the wealthier class could afford most of these items. Major consumer goods retailers such as Sears, Roebuck and Company, Montgomery Ward, and the Great Atlantic and Pacific Tea Company were eager to find lower-priced versions of these products to sell to a growing middle-class constituency. The methods of mass production that Henry Ford had popularized seemed to carry promise for these products as well. During the 1920’s, by working with such key manufacturers as Whirlpool, Hoover, General Electric, and Westinghouse, these large distributors helped introduce mass-production methods Mass-production methods[Mass production methods] into a large number of consumer-product industries. They changed class markets into mass markets.

The movement toward precision also led to the birth of a separate industry based on the manufacture of machine tools. Machine tools industry A general-purpose lathe, milling machine, or grinder could be used for a number of operations, but mass-production industries called for narrow-purpose machines designed for high-speed use in performing particular specialized steps in the production process. Many more machines were now required, one for each step in the production process. Each machine had to be simpler to operate, with more automatic features, because of an increased dependence on unskilled workers. The machine tool industry became the foundation of modern production.

The miracle of mass production that followed, in products as diverse as airplanes, communication systems, and hamburgers, would not have been possible without the precision on which Henry Leland insisted in the first decade of the twentieth century. It would not have come about without the lessons learned by Henry Ford in the use of specialized machines and assembly methods, and it would not have occurred without the growth of the machine tool industry. Cadillac’s demonstration at Brooklands in 1908 proved the practicality of precision manufacturing and interchangeable parts to the world. It inspired American manufacturers to continue to develop these ideas, and it convinced Europeans that such production was possible. For better or for worse, it played a major part in changing the world. Cadillac Motor Car Company
Inventions;interchangeable automobile parts

Further Reading

  • Hill, Frank Ernest. The Automobile: How It Came, Grew, and Has Changed Our Lives. New York: Dodd, Mead, 1967. Tells the story of the automobile industry and its growth. Includes a number of discussions of Leland’s work. Provides details on the Brooklands demonstration and discusses its consequences.
  • Hounshell, David A. From the American System to Mass Production, 1800-1932. Baltimore: The Johns Hopkins University Press, 1984. Discusses Leland’s early life, his work at the Springfield Armory, and his management of Brown and Sharpe’s sewing machine department. Provides an excellent picture of how Leland became enamored of the idea of precision manufacturing.
  • Leland, Ottilie M., and Minnie Dubbs Millbrook. Master of Precision: Henry M. Leland. 1966. Reprint. Detroit: Wayne State University Press, 1996. The primary biography of Henry Leland, coauthored by his son’s widow. Tells the story of one of the most important industrial entrepreneurs in U.S. history, an individual who played a pivotal role in the development of mass production by teaching the automobile industry the importance of interchangeable parts.
  • Marcus, Alan I., and Howard P. Segal. Technology in America: A Brief History. 2d ed. Belmont, Calif.: Wadsworth, 1998. Discusses the importance of interchangeable parts in the evolution of mass-production processes in the automobile, home appliance, and agricultural implement industries.
  • Nevins, Allan, and Frank Ernest Hill. The Times, the Man, the Company. Vol. 1 in Ford. New York: Charles Scribner’s Sons, 1954. Discusses Leland’s various relationships with Henry Ford, the Henry Ford Company, and Ford Motor Company. Briefly discusses the Brooklands demonstration.
  • Vance, Bill. Reflections on Automotive History. Vol. 1. Rockwood, Ont.: Eramosa Valley Publishing, 2000. Covers a wide range of subjects in the history of the automobile and features more than sixty black-and-white photographs. Contains a brief chapter devoted to Cadillac’s early engineering achievements, including the development of interchangeable parts.

American Automobile Association Is Established

Hashimoto Founds the Nissan Motor Company

Ford Assembly Line Begins Operation

Ford Announces a Five-Dollar, Eight-Hour Workday

General Motors Institutes a Multidivisional Structure

Number of U.S. Automakers Falls to Forty-Four