9) Herbert Hoover (Net worth: $75 million)
Herbert Clark Hoover was the 31st president of the United States of America. He held the office of the president between 1929 and 1933. Hoover was an orphan and was raised by his uncle. He made his wealth as a mining company executive. He drew a huge salary for 17 years and had extensive holdings in mining companies. He donated his presidential salary to charity. He owned “Hoover House” in Monterey, California.