Contagious diseases have long posed a public health challenge for cities, going back to the ancient world. Diseases traveled over trade routes from one city to another. Cities were also crowded and often dirty, ideal conditions for the transmission of infectious disease. The Europeans who settled North America quickly established cities, especially seaports, and contagious diseases soon followed. By the late 17th century, ports like Boston, New York, and Philadelphia experienced occasional epidemics, especially smallpox and yellow fever, usually introduced from incoming ships. Public health officials tried to prevent contagious diseases from entering the ports, most often by establishing a quarantine. These quarantines were occasionally effective, but more often the disease escaped into the cities. By the 18th century, city officials recognized an association between dirty cities and epidemic diseases. The appearance of a contagious disease usually occasioned a concerted effort to clean streets and remove garbage. These efforts by the early 19th century gave rise to sanitary reform to prevent infectious diseases. Sanitary reform went beyond cleaning streets and removing garbage, to ensuring clean water supplies and effective sewage removal. By the end of the century, sanitary reform had done much to clean the cities and reduce the incidence of contagious disease. In the 20th century, public health programs introduced two new tools to public health: vaccination and antibiotics. First used against smallpox, scientists developed vaccinations against numerous other infectious viral diseases and reduced their incidence substantially. Finally, the development of antibiotics against bacterial infections in the mid-20th century enabled physicians to cure infected individuals. Contagious disease remains a problem—witness AIDS—and public health authorities still rely on quarantine, sanitary reform, vaccination, and antibiotics to keep urban populations healthy.
Robert G. Parkinson
According to David Ramsay, one of the first historians of the American Revolution, “in establishing American independence, the pen and press had merit equal to that of the sword.” Because of the unstable and fragile notions of unity among the thirteen American colonies, print acted as a binding agent that mitigated the chances that the colonies would not support one another when war with Britain broke out in 1775.
Two major types of print dealt with the political process of the American Revolution: pamphlets and newspapers. Pamphlets were one of the most important conveyors of ideas during the imperial crisis. Often written by elites under pseudonyms and published by booksellers, they have long been held by historians as the lifeblood of the American Revolution. There were also three dozen newspaper printers in the American mainland colonies at the start of the Revolution, each producing a four-page issue every week. These weekly papers, or one-sheet broadsides that appeared in American cities even more frequently, were the most important communication avenue to keep colonists informed of events hundreds of miles away. Because of the structure of the newspaper business in the 18th century, the stories that appeared in each paper were “exchanged” from other papers in different cities, creating a uniform effect akin to a modern news wire. The exchange system allowed for the same story to appear across North America, and it provided the Revolutionaries with a method to shore up that fragile sense of unity. It is difficult to imagine American independence—as a popular idea let alone a possible policy decision—without understanding how print worked in colonial America in the mid-18th century.
The transformation of post-industrial American life in the late 20th and early 21st centuries includes several economically robust metropolitan centers that stand as new models of urban and economic life, featuring well-educated populations that engage in professional practices in education, medical care, design and legal services, and artistic and cultural production. By the early 21st century, these cities dominated the nation’s consciousness economically and culturally, standing in for the most dynamic and progressive sectors of the economy, driven by collections of technical and creative spark. The origins of these academic and knowledge centers are rooted in the political economy, including investments shaped by federal policy and philanthropic ambition. Education and health care communities were and remain frequently economically robust but also rife with racial, economic, and social inequality, and riddled with resulting political tensions over development. These information communities fundamentally incubated and directed the proceeds of the new economy, but also constrained who accessed this new mode of wealth in the knowledge economy.