Cholera is an infection of the small intestine caused by bacteria. Its major symptoms are vomiting and diarrhea, leading to dehydration. The simplest treatment is aggressive rehydratioi. Left untreated, it can lead to death.
True cholera, whose endemic home is the delta of the Ganges, did not cross the Atlantic to the New World until the 19th century. It first arrived in 1832 in New York City and within two years had wreaked devastation from Canada to the Yucatan. The second outbreak came in 1848. It was quarantined in New Orleans but escaped, crossing the Mississippi River and carried to California by gold seekers in 1849.
It struck again in New York in 1854. Three more outbreaks were reported, of diminishing intensity, the last being in 1873.