Manufacturing is the process by which raw materials or components are fabricated and assembled into finished products. Manufacturing has evolved from a relatively simple system of hand-tool production carried on within a household or workshop by individual workers into the modern \Tfactory system\t with its large, highly mechanized labor force.  This article deals primarily with manufacturing in the United States, which in its early years in many respects recapitulates the longer span of development in Europe and then parallels Europe throughout the 19th and 20th centuries.

COLONIAL MANUFACTURING

Throughout the colonial period goods produced for local consumption were largely of household or workshop manufacture. Particularly in rural areas, the spinning and weaving of woolens was common in most households, as was the making of homespun garments and even shoes.  Consumer demands in the colonial towns were usually supplied by imports or by skilled craftsmen working in small shops, who produced a variety of items, such as cloth, tailored suits, soap, candles, paper, and wine.  The only power available to colonial manufacturers, aside from that exerted by men or animals, came from \Lwaterwheel\ls, which were used principally in the production of flour and lumber.

FROM THE REVOLUTION TO THE CIVIL WAR

The American Revolution had little impact on the organization of manufacturing.  By the end of the 18th century, however, the forces of change were already gathering strength as the country turned its attention to the development of domestic sources of commodities and to the exploration of the economic potential of the region beyond the Atlantic seaboard.

By 1860, migration had reached the Pacific coast and had begun to spread into the most promising areas in the interior.  A rising tide of immigration plus a high domestic birthrate combined to increase the population from 3.9 million in 1790 to 31.5 million in 1860.  Both the total growth of the population and its westward movement opened up economic opportunities for the eastern states.

Against this background manufacturing began to expand and acquire some of its modern characteristics.  Much of the stimulus for this development came from Great Britain, which at the time was in the midst of the \TIndustrial Revolution\t. Certain basic manufacturing techniques developed by the British during this period, notably the factory system of industrial organization and the use of fossil \Lfuel\ls for energy, proved especially adaptable to the U.S.  situation.  The relative scarcity of labor in the New World compared to the adequate work force in Britain made the factory system particularly attractive to American entrepreneurs.

Beginnings of the U.S. Factory System

In 1790, Samuel \TSlater\t, a one-time employee of Richard \TArkwright\t who had learned the latter's methods for mechanized spinning of cotton in England, successfully built the equipment for a spinning factory in Pawtucket, R.I.  Slater's success not only launched the domestic cotton textile industry but also established a pattern for the future growth of manufacturing in the United States.  Initial progress was slow, however, because it was difficult to acquire patterns for the first machines for factory production, labor was scarce, and the capital necessary to start even a small mill was not easy to command.

By mid-century most of these problems had been overcome.  Faced with a scarcity of accumulated funds, entrepreneurs adopted the corporation as a device for assembling capital.  An expanding group of skilled mechanics increased the availability of machinery, and higher wages attracted the workers to operate them.  By this period, the factory system had been extended to the production of woolens, lumber, flour, shoes, paper, and iron.  Primarily dependent on water power for energy, the movement was largely confined to Massachusetts, Connecticut, Rhode Island, and Pennsylvania.

As early as 1810 the pressure to economize on the use of labor, particularly skilled labor, had prompted two technical innovations--continuous-process manufacture and interchangeable-parts production--that were to distinguish U.S. manufacturing methods from those followed outside the United States.

Continuous-Process Production

Continuous-process manufacture, in which production is so arranged that materials move smoothly through successive processing stages, was originated by Oliver \TEvans\t, who in 1784 introduced the system in a flour mill he had built in Delaware. In order to reduce to a minimum the amount of labor involved in the milling process, Evans designed a power-driven \Tconveyor\t system that moved grain from one machine to another and from one floor to another.  This process subsequently became a characteristic feature of factory operations.

Interchangeable Parts

Although the idea of interchangeability was of European origin, it was not until the turn of the 19th century that Connecticut arms makers Eli \TWhitney\t and Simeon North began the experiments that led to interchangeable-parts manufacture, in an attempt to improve the long-established methods of producing firearms. Arms had previously been made with hand tools by individual craftsmen;  component parts were not interchangeable, and each weapon had to be individually fitted.  Thus the breaking of one part of a gun or pistol meant that a new piece had to be made and fitted by an expert armorer.

Whitney and North revolutionized the arms-making process and cut labor costs in two ways:  they trained each employee to specialize in a separate weapon part, and they developed tools and power-driven equipment capable of turning out standard, interchangeable components.

By the 1850s impressive advances had been made in improving the speed and accuracy of the machines utilized earlier by Whitney and North.  Many of these improvements came from the expanding machine-tool industry, which by mid-century was prepared to supply standardized machines or to build special equipment for customers.  The system of interchangeable-parts manufacture had also been extended to the production of clocks, agricultural equipment, and sewing machines.

Although still subordinate to agriculture, manufacturing by 1860 had clearly earned a secure place in the U.S.  economy. In that year, according to the census, 140,000 manufacturing establishments, most of them still small, employed 1.3 million workers, 20 percent of the nation's entire labor force, and contributed more than $854 million to a gross national product (\TGNP\t) of approximately $4.2 billion.

1860-1920

During the period between the Civil War and the end of World War I the U.S.  economy took on most of its modern characteristics.  The change that stands out above all others was the shift from an agricultural economy to an industrial economy, a change that by the 1890s made the United States the world's leading industrial nation.

In large part, the change reflected the influence on manufacturing of several improvements in technology.  One improvement was the introduction of more efficient and flexible methods of using energy, notably the widespread adoption of the high-pressure \Tsteam engine\t and the utilization of electricity (see \Tpower, generation and transmission of\t).  These developments not only relieved manufacturers of the necessity of locating at waterpower sites but also made coal the chief source of energy for industrial production.  A second factor was an improved process of producing metals, particularly iron and steel (see \Tiron and steel industry\t), which increased the quality of materials used both in the construction of machinery and equipment and in the fabrication of consumer goods.  A third development was the further growth of the \Tmachine tool\t industry that supplied machines adapted to the requirements of increasingly complex manufacturing operations.  The final improvement was the large-scale \Tmass production\t technology of Henry Ford (see \TFord\t family), who by 1914 had combined interchangeable-parts and continuous-flow manufacture to establish what is popularly known as the \Tassembly line\t.

These advances were manifested by the proliferation of mechanized industries, which by World War I were turning out huge quantities of standardized products ranging from meat, bread, canned fruits and vegetables, and bottled beverages to hardware, ready-made clothing, clocks, watches, typewriters, bicycles, and farm machinery.

Between 1860 and 1920 factory employment rose from 1.3 million to just under 10 million, while output, measured in terms of value added to the \TGNP\t, grew from $854 million to $24 billion. By the 1890s the manufacturing sector had already surpassed agriculture as a generator of national income;  by 1920 its share of nearly one-third of the \TGNP\t was more than twice that of agriculture.  This growth would not have been possible without a corresponding expansion of the market.  Basic to this expansion was an increase in population from 31.5 million to more than 104 million and a fourfold increase in per capita income.  No less important in fostering a large common domestic market was the expansion of the railway network that linked consumers and producers hundreds and even thousands of kilometers apart.  Widespread abuse of the labor force, such as 12- to 14-hour workdays and \Tchild labor\t, also marked this phase of industrial development.  The result was the rise and proliferation of strong \Llabor union\ls.

1920-1980

Despite fluctuations in employment and production, manufacturing grew impressively during the years following World War I.  By 1977 the manufacturing labor force of close to 20 million was more than double that for 1920, and output (measured in constant 1920 dollars) had expanded nearly sixfold, from $24 billion to $129 billion.

Both the growth rate and structure of manufacturing were modified and strengthened by the introduction of a number of important innovations, which in some instances led to the creation of new industries and in others to improvements in the productive efficiency of old ones.  A growing electric-power industry spawned an impressive array of electrically operated consumer products, including radios, television sets, blankets, dehumidifiers, and home freezers.  The internal-combustion engine in its various forms--gasoline, gas, and diesel--found increasing application in industry and in land and air transportation.

Of prime importance in their industrial impact were developments in the fields of chemistry and chemical engineering.  A major feature of these developments was the introduction of methods by which such familiar products as fertilizer and rubber could be produced artificially.  Even more innovative was the introduction of technology for the synthetic manufacture of a great variety of entirely new materials:  coal-tar dyes;  explosives;  the well-known synthetic fibers (rayon, dacron, and orlon);  and plastics, which were widely used in the fabrication of a host of industrial and consumer products (see \Tchemical industry\t).

Increasing mechanization of labor remained the essential feature of the evolution of manufacturing methods during these years, especially as the mass-production technology pioneered by Ford spread to the production of such items as refrigerators, washing machines, and aircraft, all of which require precise and accurate assembly.The innovation with perhaps the greatest implication for the future of large-scale mass manufacturing was the extension during the 1950s of \Tautomation\t, automatic controls over manufacturing processes. The logical result of the long trend in the increasing use of labor-saving machinery, fully developed automation involves the movement of materials through an entire production sequence under the guidance and control of a computer (see \Tprocess control\t).  An important development in this area in the 1970s was the industrial \Trobot\t, a computer-controlled machine that could replace human labor in repetitive or hazardous tasks, such as welding, spray-painting, and materials handling.

By the 1970s, U.S.  manufacturing had begun to suffer from one of the factors that had ended British industrial domination nearly a century earlier:  a "maturing," or aging, physical plant.  The relatively slow pace of modernization in the United States left the nation with outdated plants and machinery compared to, for example, the Japanese and West Germans, who had been forced to rebuild almost completely after World War II.  The Japanese, in particular, were quick to seize upon new manufacturing technology;  by 1981, for example, they employed fully half of the world's industrial robots and were rapidly overtaking the United States in the new field of microelectronics, a U.S.  invention.  Modern technology, along with innovative labor-relations policies, enabled both Japan and West Germany to show extraordinary rates of both absolute and productivity growth, whereas in the United States productivity growth actually dropped below zero in 1979.

Another trend in U.S.  manufacturing after World War II was a dramatic shift of resources to the service sectors of the economy, such as trade, transportation, and communications. This had the effect of draining employees and funds away from the manufacturing sector and increased the difficulties of modernizing.  Thus it seemed possible that the United States would eventually be replaced as the world's largest producer in many areas of manufacturing.  At the same time, the switch to service industries in the United States may indicate the path that will eventually be followed by other industrialized economies.

THE LATE 1980s AND BEYOND

Beginning in the 1980s, forward-looking U.  S.  manufacturers began assessing the potential of \Tcomputer-aided design and computer-aided manufacturing\t (CAD-\TCam\t) to create new factory systems.  Originally, computers had been used in factories almost entirely to control the flow of materials.  Other automated factory devices, such as robots, were confined to performing repetitive and relatively simple actions such as spot welding.  Most of the processes of manufacturing were still accomplished by human hands.

Today, using advanced technologies that begin with the computer design of product parts, entire assemblies can be computer controlled, a development known as Computer Integrated Manufacturing (CIM).  On its simplest level, computer design produces parts that are cheaper and easier to assemble. Connected with automated machine tools, however, computers can aid in the manufacture of higher-quality, longer-lived parts that often can be robotically assembled.  As machinery is automated, flexibility in manufacturing increases, allowing for a wide variety of products to be made and changeovers to take place within a short time, without the retooling that was once necessary.  Smaller manufacturing units prove more efficient than the cavernous factory spaces of the past.  The installation of CIM systems is costly, but manufacturers find that they pay for themselves quickly, while labor costs plummet.  Although the implications of CIM for the future of the U.  S.  labor force are unclear, the technique's value as a manufacturing tool is already being proven.

Harold F. Williamson

Bibliography:  Bernal, J.  D., Science and Industry in the 19th Century (1970);  Chorafas, D.  N., Engineering Productivity through CAD-\TCam\t (1986);  Dosi, G., Technical Change and Industrial Transformation (1984);  Gunderson, Gerald, A New Economic History of America (1976);  Habakkuk, H.  J., American and British Technology in the 19th Century (1962);  Kranzberg, Melvin, and Pursell, Carroll, Technology in Western Civilization, 2 vols.  (1967);  Martin, R., and Rawthorn, R., The Geography of De-Industrialization (1986);  Medland, A.  J., and Burnett, P., CAD-\TCam\t in Practice (1986);  Pursell, Carroll W., Jr., ed., Technology in America:  A History of Individuals and Ideas (1981).

See also:  \Tgovernment regulation\t;  \Tpollution, environmental\t; \Ttechnology, history of\t.