John Menard Jr., Wisconsin
Menard's $11.4 billion net worth is thanks to his home improvement retailer. His stores compete with Home Depot and Lowe's and are based in the middle of the U.S., from Wyoming to Ohio. He's brought in an estimated $10 billion in sales.
John Mars, Wyoming
Another one-third shareholder of Mars Inc., John Mars has a net worth of $28.1 billion. When their father died in 1999, all three Mars siblings earned a third of the company. Mars' first success was the Milky Way bar in 1923.