Wal-Mart is Coming Wal-Mart Stores, Inc. (branded as Walmart) is an American public corporation that runs a chain of large, discount department stores. It is the world's largest public corporation by revenue, according to the 2008 Fortune Global 500. Wal-Mart is the largest private employer and the largest grocery retailer in the United States. It also owns and operates the Sam's Club retail warehouses in North America.