McDonald's is the world's largest chain of hamburger fast food restaurants, serving around 68 million customers daily in 119 countries across 35,000 outlets.[4][5] Founded in the United States in 1940, the company began as a barbecue restaurant operated by Richard and Maurice McDonald. In 1948, they reorganized their business as a hamburger stand using production line principles. Businessman Ray Kroc joined the company as a franchise agent in 1955. He subsequently purchased the chain from the McDonald brothers and oversaw its worldwide growth.[6]