Doug McMillon's first job at Wal-Mart was unloading trucks at a distribution center in Arkansas.

Over the course of his career, McMillon has been in just about every job at Wal-Mart. He quickly made his way from a buyer in an Oklahoma store to a series of management positions at the headquarters in Bentonville, Ark. He followed the same career path as current CEO Michael Duke, who he'll replace next year, and previously ran Sam's Club and the company's international operations.