Who was the world's first billionaire?

• A. J. P. Morgan
• B. John D. Rockefeller
• C. Andrew Carnegie
• D. Cornelius Vanderbilt

Answer: (B)

A billionaire is someone whose wealth is on the order of one billion dollars. John D. Rockefeller built Standard Oil into a vast, highly profitable empire by controlling refining, distribution, and pipelines, driving profits to enormous levels. By the 1910s his fortune was estimated to exceed the billion-dollar mark in nominal terms, making him the first person commonly recognized as a billionaire. The other ultra-wealthy names—J. P. Morgan in finance, Andrew Carnegie in steel, and Cornelius Vanderbilt in rail and shipping—were incredibly rich, but their fortunes did not reach the billion-dollar threshold in the same era. Rockefeller’s combination of scale, timing, and industry dominance explains why he is regarded as the first billionaire.