John D. Rockefeller, born in 1839 into relatively modest circumstances, became the world’s first billionaire in 1916 after creating the first major business trust. By some accounts, he is still the richest man to have ever lived.
The Rockefellers also created the Standard Oil Company, which came to define monopolistic business practices in the US. They've also financed American institutions such as New York City's Rockefeller Center, Colonial Williamsburg, and more.
Today, the Rockefeller family has a cumulative net worth of $10.3B. Their modern-day influence mostly involves charitable giving to causes like higher education, the environment, and national parks. Their moneyed reputation has outlasted John D. Rockefeller himself: Taylor Swift, for instance, recently referenced the Standard Oil fortune in a popular song.