"was the classic epidemic disease of the nineteenth century, as had been of the . When cholera first appeared in the United States in 1832, and smallpox, the great epidemic diseases of the previous two centuries, were no longer truly national problems. Yellow fever had disappeared from the , and had deprived smallpox of much of it menace. Cholera, on the other hand, appeared in almost every part of the country in the course of the century. ... Before 1817, there had probably never been a cholera epidemic outside the ; during the nineteenth century, it spread through almost the entire world ..."