History of Science and Technology

Radio debuted as a wireless alternative to telegraphy in the late 19th century. At its inception, wireless technology could only transmit signals and was incapable of broadcasting actual voices. During the 1920s, however, it transformed into a medium primarily identified as one used for entertainment and informational broadcasting. The commercialization of American broadcasting, which included the establishment of national networks and reliance on advertising to generate revenue, became the so-called American system of broadcasting. This transformation demonstrates how technology is shaped by the dynamic forces of the society in which it is embedded. Broadcasting’s aural attributes also engaged listeners in a way that distinguished it from other forms of mass media. Cognitive processes triggered by the disembodied voices and sounds emanating from radio’s loudspeakers illustrate how listeners, grounded in particular social, cultural, economic, and political contexts, made sense of and understood the content with which they were engaged. Through the 1940s, difficulties in expanding the international radio presence of the United States further highlight the significance of surrounding contexts in shaping the technology and in promoting (or discouraging) listener engagement with programing content.

By the end of the 19th century, the medical specialties of gynecology and obstetrics established a new trend in women’s healthcare. In the 20th century, more and more American mothers gave birth under the care of a university-trained physician. The transition from laboring and delivering with the assistance of female family, neighbors, and midwives to giving birth under medical supervision is one of the most defining shifts in the history of childbirth. By the 1940s, the majority of American mothers no longer expected to give birth at home, but instead traveled to hospitals, where they sought reassurance from medical experts as well as access to pain-relieving drugs and life-saving technologies. Infant feeding followed a similar trajectory. Traditionally, infant feeding in the West had been synonymous with breastfeeding, although alternatives such as wet nursing and the use of animal milks and broths had existed as well. By the early 20th century, the experiences of women changed in relation to sweeping historical shifts in immigration, urbanization, and industrialization, and so too did their abilities and interests in breastfeeding. Scientific study of infant feeding yielded increasingly safer substitutes for breastfeeding, and by the 1960s fewer than 1 in 5 mothers breastfed. In the 1940s and 1950s, however, mothers began to organize and to resist the medical management of childbirth and infant feeding. The formation of childbirth education groups helped spread information about natural childbirth methods and the first dedicated breastfeeding support organization, La Leche League, formed in 1956. By the 1970s, the trend toward medicalized childbirth and infant feeding that had defined the first half of the century was in significant flux. By the end of the 20th century, efforts to harmonize women’s interests in more “natural” motherhood experiences with the existing medical system led to renewed interest in midwifery, home birth, and birth centers. Despite the cultural shift in favor of fewer medical interventions, rates of cesarean sections climbed to new heights by the end of the 1990s. Similarly, although pressures on mothers to breastfeed mounted by the end of the century, the practice itself increasingly relied upon the use of technologies such as the breast pump. By the close of the century, women’s agency in pursuing more natural options proceeded in tension with the technological, social, medical, and political systems that continued to shape their options.

Energy systems have played a significant role in U.S. history; some scholars claim that they have determined a number of other developments. From the colonial period to the present, Americans have shifted from depending largely on wood and their own bodies, as well as the labor of draft animals; to harnessing water power; to building steam engines; to extracting fossil fuels—first coal and then oil; to distributing electrical power through a grid. Each shift has been accompanied by a number of other striking changes, especially in the modern period associated with fossil fuels. By the late 19th century, in part thanks to new energy systems, Americans were embracing industrialization, urbanization, consumerism, and, in a common contemporary phrase, “the annihilation of space and time.” Today, in the era of climate change, the focus tends to be on the production or supply side of energy systems, but a historical perspective reminds us to consider the consumption or demand side as well. Just as important as the striking of oil in Beaumont, Texas, in 1901, was the development of new assumptions about how much energy people needed to sustain their lives and how much work they could be expected to do. Clearly, Americans are still grappling with the question of whether their society’s heavy investment in coal- and petroleum-based energy systems has been worthwhile.

The development of nuclear technology had a profound influence on the global environment following the Second World War, with ramifications for scientific research, the modern environmental movement, and conceptualizations of pollution more broadly. Government sponsorship of studies on nuclear fallout and waste dramatically reconfigured the field of ecology, leading to the widespread adoption of the ecosystem concept and new understandings of food webs as well as biogeochemical cycles. These scientific endeavors of the atomic age came to play a key role in the formation of environmental research to address a variety of pollution problems in industrialized countries. Concern about invisible radiation served as a foundation for new ways of thinking about chemical risks for activists like Rachel Carson and Barry Commoner as well as many scientists, government officials, and the broader public. Their reservations were not unwarranted, as nuclear weapons and waste resulted in radioactive contamination of the environment around nuclear-testing sites and especially fuel-production facilities. Scholars date the start of the “Anthropocene” period, during which human activity began to have substantial effects on the environment, variously from the beginning of human farming roughly 8,000 years ago to the emergence of industrialism in the 19th century. But all agree that the advent of nuclear weapons and power has dramatically changed the potential for environmental alterations. Our ongoing attempts to harness the benefits of the atomic age while lessening its negative impacts will need to confront the substantial environmental and public-health issues that have plagued nuclear technology since its inception.

Over the course of the 19th century, American cities developed from small seaports and trading posts to large metropolises. Not surprisingly, foodways and other areas of daily life changed accordingly. In 1800, the dietary habits of urban Americans were similar to those of the colonial period. Food provisioning was very local. Farmers, hunters, fishermen, and dairymen from a few miles away brought food by rowboats and ferryboats and by horse carts to centralized public markets within established cities. Dietary options were seasonal as well as regional. Few public dining options existed outside of taverns, which offered lodging as well as food. Most Americans, even in urban areas, ate their meals at home, which in many cases were attached to their workshops, countinghouses, and offices.

These patterns changed significantly over the course of the19th century, thanks largely to demographic changes and technological developments. By the turn of the 20th century, urban Americans relied on a food-supply system that was highly centralized and in the throes of industrialization. Cities developed complex restaurant sectors, and majority immigrant populations dramatically shaped and reshaped cosmopolitan food cultures. Furthermore, with growing populations, lax regulation, and corrupt political practices in many cities, issues arose periodically concerning the safety of the food supply. In sum, the roots of today’s urban food systems were laid down over the course of the 19th century.

The eighty years from 1790 to 1870 were marked by dramatic economic and demographic changes in the United States. Cities in this period grew faster than the country as a whole, drawing migrants from the countryside and immigrants from overseas. This dynamism stemmed from cities’ roles as spearheads of commercial change and sites of new forms of production. Internal improvements such as canals and railroads expanded urban hinterlands in the early republic, while urban institutions such as banks facilitated market exchange. Both of these worked to the advantage of urban manufacturers. By paying low wages to workers performing repetitive tasks, manufacturers enlarged the market for their products but also engendered opposition from a workforce internally divided along lines of sex and race, and at times slavery and freedom. The Civil War affirmed the legitimacy of wage labor and enhanced the power of corporations, setting the stage for the postwar growth of large-scale, mechanized industry.

Urban water supply and sewage disposal facilities are critical parts of the urban infrastructure. They have enabled cities and their metropolitan areas to function as centers of commerce, industry, entertainment, and human habitation. The evolution of water supply and sewage disposal systems in American cities from 1800 to 2015 is examined, with a focus on major turning points especially in regard to technological decisions, public policy, and environmental and public health issues.