3. John Rockefeller: $ 340 billion (321 billion euros)
American industrialist and philanthropist, and obviously founder of the legendary Rockefeller family. His family was at the head of an empire for nearly two centuries by creating Standard Oil which became Esso and ExxonMobil. John Rockefeller retires in 1896 being the richest man in the United States and one of the most powerful in the world. His son took over the company.