8. Andrew Carnegie – peak net worth: $337 billion
From humble beginnings in Scotland, Andrew Carnegie led the massive expansion of the US steel industry in the late 19th century, amassing a personal fortune economists estimate would be worth $337 billion nowadays. A full-on philanthropist, Carnegie gave away 90% of his fortune to various charities and educational establishments during the last years of his life.
7. John D. Rockefeller – peak net worth: $367 billion
Widely regarded as the richest American who ever lived, John D. Rockefeller founded the Standard Oil company in 1870 and ended up controlling around 90% of the US oil business. Economist Peter Bernstein estimates that the industrialist-turned-philanthropist had a personal fortune of $367 billion in today’s money.