John Snow was born on 15 March 1813 in York, England, the son of a coal worker. At age 14, he was apprenticed to a surgeon and physician who was a friend of the family, an event that marked the beginning of Snow's career in medicine. He later studied at the University of London, graduating in 1844, and was admitted to the Royal College of Physicians in 1850.
To students of statistics, Snow is remembered for his statistical study of the 1854 cholera epidemic in London. Snow believed that cholera was spread by contaminated water, contrary to the prevailing miasma view of the time that the disease was spread by foul air. To support his view, Snow collected data on the location (street addresses) of persons who died in the epidemic, as well as data on the location of water pumps in the city. The data showed geographical clustering of deaths, particularly near the Broad Street pump. His analysis was sufficiently convincing that government officials removed the handle of the Broad Street pump in an attempt to curb the spread of the disease. Snow's work was a seminal event in the history of statistics, as one of the first statistical epidemiological studies and one of the first uses of statistical clustering.
John Snow died of a stroke at age 45 on 16 June 1858 in London.