Who was the first person to have one billion U.S. dollars?

A billionaire is a person with a net worth of at least one billion (1,000,000,000, i.e., a thousand million) units of a given currency, usually of a major currency such as the United States dollar, euro, or pound sterling. It is a sub-category of the concept of the ultra high-net-worth individual. The American business magazine Forbes produces a global list of known U.S. dollar billionaires every year and updates an Internet version of this list in real-time. The American oil magnate John D. Rockefeller became the world's first confirmed U.S. dollar billionaire in 1916.

John Davison Rockefeller Sr. (July 8, 1839 – May 23, 1937) was an American business magnate and philanthropist. He has been widely considered the wealthiest American of all time and the richest person in modern history.

Rockefeller's wealth soared as kerosene and gasoline grew in importance, and he became the richest person in the country, controlling 90% of all oil in the United States at his peak.