Doug McMillon got his start as an hourly worker. He worked a summer job at Walmart unloading trucks when he was a teenager in 1984. 30 years later, McMillon took over Walmart as its CEO.

When Wal-Mart announced that Doug McMillon would become the retailer's fifth ever CEO starting in February, only the timing was a surprise. McMillon, 47, has steadily risen up the company's ranks ...

Doug McMillon is a rare phenomenon in modern business. Not only does his career span a remarkable four decades with the same company, he's on the short list of CEOs who started on the very bottom ...