Portrait of John D. Rockefeller taken in

Portrait of John D. Rockefeller taken in the mid 1930's in Ormond, Florida. Born in Richford, New York in 1939 he studied in Cleveland and took a business course at Folsom Mercantile Colege, completing a six-month course in three months. In 1859, he started his own produce commission business with a partner, Maurice Clark. Clark & Rockefeller quickly became a successful firm, and its partners accumulated enough capital to invest in other Cleveland businesses. In 1863, they invested in an oil refinery with chemist Samuel Andrews. Undeterred, Rockefeller continued with his self-reinforcing cycle of buying competing refiners, improving the efficiency of his operations, pressing for discounts on oil shipments, undercutting his competition, and buying them out. In six weeks in 1872, Standard Oil had absorbed 22 of his 26 Cleveland competitors.Standard Oil gradually gained almost complete control of oil production in America. Rockefeller married Laura Celestia in 1864 and had four daughters and one son John D. Jr. who inherited much of the family business and continued his father philanthropic work. (Photo credit should read STF/AFP via Getty Images)