With net worth $39 billion Berkshire Hathaway Inc. chairman Warren Buffett is in second position on the list.
Oracle CEO Larry Ellison completes the top three richest Americans post with a net worth of $33 billion.
Forbes said the combined assets of the 400 people on this year’s list are $1.5 trillion, a 12% increase than last year. 18 people made it to the Forbes 400 list for the first time including Napster co-founder Sean Parker (200), and owner of the Boston Red Sox and Liverpool John Henry (375).
Facebook founder Mark Zuckerberg (14) was the biggest gainer of the year with net worth of $17.5 billion.
There were 42 women on the list, including Oprah Winfrey (139) with a net worth of $2.7 billion.
The top 10 people on this year’s Forbes 400 list are:
1. Bill Gates ($59 billion)
2. Warren Buffett ($39 billion)
3. Larry Ellison ($33 billion)
4. Charles Koch ($25 billion)
5. David Koch ($25 billion)
6. Christy Walton & family ($24.5 billion)
7. George Soros ($22 billion)
8. Sheldon Adelson, ($21.5 billion)
9. Jim Walton ($21.1 billion)
10. Alice Walton ($20.9 billion)