Microsoft co-founder Bill Gates is still America's richest man, taking the top spot in the Forbes 400 list for the 20th-straight year with a net worth of 72 billion dollars (£45.2 billion).
Investor Warren Buffett, the head of Berkshire Hathaway, remains in second place with 58.5 billion dollars (£36.72 billion), while Oracle co-founder Larry Ellison stays third with 41 billion dollars (£26 billion).
Forbes says America's super rich continued to increase their wealth over the past year, with the 400 people on the annual list posting a combined net worth of 2 trillion dollars (£1.26 trillion), up from 1.7 trillion dollars (£1.07 trillion) a year ago. That marks their highest combined value ever.
Forbes attributed the growth to strong stock and property markets.