17. Samuel Robson Walton
Estimated net worth: $26.1 billion
Walton, pictured, is the chairman of the board of directors for Walmart, the mega shopping company that his father, Sam Walton, started. He has been a member of the board since 1978, according to Walmart.
16. Alice Walton
Estimated net worth: $26.3 billion
Alice Walton is the youngest child of Walmart's founder. She is currently the chairman of Crystal Bridges Museum of American Art and is considered the most generous philanthropist of her family.