BRIEF HISTORY DURING THE SNOW ERA (1813-58)

Cholera epidemics visited England three times during the life of John Snow.  The first was in 1831-2, before John Snow came to London.  The second was in 1848-9 and the third was in 1853-4.  Of the first London case in 1848, John Snow wrote:

"The first case of decided Asiatic cholera in London, in the autumn of 1848, was that of a seaman named John Harnold, who had newly arrived by the Elbe steamer from Hamburgh, where the disease was prevailing.  He left the vessel, and went to live at No. 8, New Lane, Gainsford Street, Horsleydown.  He was seized with cholera on the 22nd of September, and died in a few hours. Dr. Parkes, who made an inquiry into the early cases of cholera, on behalf of the then Board of Health, considered this as the first undoubted case of cholera."

- Snow, John. Communication of Cholera, 1855, p. 3 

More on the early aspects of the 1848-9 epidemic is in part 1 of John Snow's book.  The home of the first cholera case is not specifically shown on the 1859 map, but is located to the west of the vertical "m" in Shad Thames Street in the lower left corner of N 25.  

The 1846 (nearest in time to the event), 1862 and 1872 maps show the exact home location of the first case.