The first Walmart store opened in 1962 and it was the No. 1 retailer in the US by 1990.

Sam Walton never forgot who the top dog in his operation was. "There is only one boss: the customer," the Wal-Mart (WMT) co-founder once said. "And he can fire everybody in the company, from the ...

Beginnings and Ben Franklin -- The evolution of retailing and the appearance of discount merchandising -- The birth of Wal-Mart -- A billion-dollar baby: Wal-Mart during the 1970's -- Wal-Mart becomes ...