In 1916, John D. Rockefeller was credited as the first person in the United States to become a billionaire, according to The Motley Fool. Rockefeller formed the Standard Oil company in 1870, investing $300,000 of his own money. By 1916 the stock was nearly $2 billion dollars.
Rockefeller was born in 1839 as the second of six children. He began his career as a bookkeeper in a produce commission firm in September 1855 before starting his own firm with Maurice B. Clark in 1859. In 1866, Rockefeller went into partnership with his brother at an oil refinery in Cleveland. In 1870, Rockefeller then moved on to his own refinery in Ohio, Standard Oil, which made him his billions.