By the early nineteenth century, outbreaks of deadly disease had long been commonplace in New York City. Smallpox, Yellow Fever, measles, and malaria recurrently plagued residents as they carved a city out of the marshes of Manhattan Island. New York's developing role as an entrepot for trade between the American interior and the Atlantic world contributed to the city's susceptibility to disease. Sailors and traders from far-off ports brought with them fresh strains of familiar diseases, and new settlers added to the city's problems in dealing with refuse. Most of these diseases were seasonal and epidemic: they usually would hit unexpectedly, run their course quickly and ferociously, and then disappear. Early 19th-century medical knowledge was incapable of dealing effectively with such outbreaks. Competing notions of what caused disease to spread tended to slow and scatter communal responses. Further, in the years before the medical field was professionalized, any crackpot with an idea was given space to experiment. More often than not, treatments for disease in early nineteenth century New York were just as likely to harm patients as to help; and some well-respected treatments of the day, such as "bleeding," could actually further spread disease. A weak city government unwilling to take on the cost of investigating and pursuing methods of containing or eradicating disease, and also only marginally interested in addressing sanitation problems, contributed further to the city's susceptibility to epidemics. The city's Common Council appointed a standing board of health in 1805, but it possessed little significant power to act. Beyond the occasional quarantine, little municipal effort arose to meet the threat of disease. Epidemics, it was assumed, were a part of life. The fact that disease caused significantly greater suffering in the poorer neighborhoods of New York City contributed to the blasé responses of city leaders. Disease could be and was written off as punishment for the moral laxity and intemperance of poor New Yorkers. Why else, in an era before medical science fully understood the linkages between sanitation and disease, would poorer neighborhoods be hit the hardest? Contemporary notions of mortality and morality influenced the responses of city leaders in politics and business to the outbreak of disease. Cholera, transmitted by contaminated food and water, causes diarrhea and vomiting so severe that death by dehydration is possible if the symptoms are left untreated. When the disease arrived in New York City in Summer 1832, after traveling over trade routes from India through Russia and Europe across the Atlantic to Canada and down the Hudson River Valley, thousand of citizens died within weeks. Cholera struck again in 1849 and 1866 before New Yorkers learned how to contain the disease. Measuring the reaction of New Yorkers to these increasingly traumatic public health disasters shows how understandings of disease were filtered through contemporary ideas about class and social relations, conceptions of immigrants, and thinking about the responsibilities of the city's government in issues of public health in mid-nineteenth century New York.