The Walmart heirs are worth $330 billion. Sam Walton's smart move in the 1950s is a big reason why.

• The Walton family is worth more than $330 billion, dwarfing Elon Musk's $237 billion fortune.
• They owe some of their wealth to a savvy decision by Walmart founder Sam Walton over 70 years ago.
• Walton structured the company as a family partnership with 20% stakes for his four young children.

The Walton family is worth about $330 billion, or way more than Elon Musk ($237 billion), per the Bloomberg Billionaires Index. Its members owe a chunk of their incredible wealth to a shrewd move by Walmart founder Sam Walton in the 1970s.