Biography on CNBC The Rockefellers

A Dynasty Built On Oil

John D. Rockefeller came from humble beginnings, but that changed in the 1880s when he took a risk in the oil business and became the founder of Standard Oil Corporation. That risk lead to the multi-billion-dollar fortune that allowed generations of Rockefellers to make a huge difference in America as philanthropists, realtors and politicians.

What was the greatest gamble of John D. Rockefeller Jr's career?