The Ten Biggest Family Businesses in the U.S. Business Insurance lists them: Wal-Mart Wal-Mart is the world's largest retailer and most successful family business of all time. In 1962, founder Sam Walton took his knowledge of discount retailing and opened the first Wal-Mart store in Rogers, Ark. It wasn't long before Sam expanded his business and opened up hundreds, then thousands of stores worldwide. After ...