Meet the family whose business has been the No. 1 Fortune 500 company for 6 straight years

Rob Walton, chairman of Wal-Mart Stores Inc. and son of Wal-Mart founder Sam Walton, right, stands on stage with his siblings Alice Walton, center and Jim Walton, at the company's annual shareholders meeting in Fayetteville, Arkansas, U.S., on Friday, June 4, 2010.
Beth Hall | Getty Images

For the sixth year in a row and the 14th time, total, Walmart has secured the No. 1 spot on the Fortune 500 list.

With revenue of $500.3 billion, the retailer tops the annual list of America's largest companies, which was released on Monday. Exxon Mobil places second with a revenue of $244.4 billion, roughly half of Walmart's, while Berkshire Hathaway, Apple and UnitedHealth Group round out the top five.

Walmart has made the Fortune 500 list 24 times since the magazine published the first list in 1955, and over half of those times it has been No. 1.

Founder Sam Walton first envisioned something more modest: A retail business that would serve rural areas and "help customers, cut costs and share profits."

While getting his degree in economics at the University of Missouri at Columbia in the 1930s, Walton waited tables, delivered newspapers and clerked at a five-and-dime. He opened the first Walmart store in Arkansas in 1962.

His company grew rapidly and went public in 1970. Sales associates who had remained with the company and received Walmart shares saw their own wealth grow, CNBC anchor David Faber reports in the documentary "The Age of Walmart."

Ever since Walton gave up his role as CEO in 1988, the company has been led by four chief executives: David Glass, Lee Scott, Michael Duke and current CEO Doug McMillon, none of whom was directly related to him.

These billionaires are handing over their fortune to charity and not their kids
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Walton and his wife Helen raised four children: Rob, John, Jim, and Alice. In 1992, President George H. W. Bush awarded Walton the Presidential Medal of Freedom. The Walmart founder passed away the same year. By then, his family was already the richest in the nation, and his New York Times obituary called him "the most successful merchant of his time." Yet he drove a Ford F-150 Custom pickup from 1979 until he died over a decade later.

He famously said, "Why do I drive a truck? What am I supposed to haul my dogs around in, a Rolls-Royce?" The car is now on display at the Walmart Museum in Bentonville, Arkansas.

Walton's son John died in a plane crash in 2005 and Helen died in 2007. The surviving three children own about 50 percent of Walmart's stock and they and their families still help lead the business.

Rob, the 15th richest person in the world, was chairman for over two decades after his father passed away in 1992. His son-in-law Greg Penner took over in 2015. "He was smart enough to marry my daughter," the outgoing chairman joked in explanation at that year's shareholder's meeting, according to the Wall Street Journal.

Jim, the 16th richest person in the world, sat on Walmart's board for more than a decade before handing the seat over to his son, Steuart, in 2016. Together with Alice, he runs the family's holding company, Walton Enterprises, the company's biggest shareholder.

Today, heiress and philanthropist Alice is the world's richest woman, according to the Forbes 2018 billionaires list. The youngest of Sam Walton's children, Alice is reportedly worth $40.2 billion, yet she too drove a Ford F-150 worth a relatively modest $40,000.

"My parents didn't believe value and worth had anything to do with money. I think it's always been important to keep your feet on the ground and your nose out of the air," she told CBS News.

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