John Graunt (1620-1674) is considered by many historians to have founded the science of demography, the statistical study of human populations. He analyzed the vital statistics of the citizens of London and wrote a book regarding those figures that greatly influenced the demographers of his day and those in the centuries that followed. Graunt was honored for his work by being made a charter member of England's Royal Society, which was composed of prominent scientists.

John Graunt was born in London, England, on April 24, 1620, to Henry Graunt, a storekeeper in Hampshire, and his wife, Mary. The eldest of seven or eight children, Graunt attended school until adolescence. At age sixteen he became an apprentice to his father, who was employed as a draper (a dealer in clothing and dry goods). In February 1641, Graunt married Mary Scott, with whom he had one son and three daughters.

As his career...