Entrepreneur. He was a successful American businessman with a passion for perfection, who created the McDonald's fast-food restaurant empire. At age 15, he lied about his age to join the American Red Cross ambulance service to serve in World War I. The war ended in 1918 and for the next two decades, he worked various jobs in his native Chicago. In 1948, as a milkshake mixer salesman, traveling across the country, he took note when the McDonald Brothers (Maurice & Richard) of San Bernardino, California, purchased eight of his multi-shake mixers. He visited their restaurant and became convinced that he could sell mixers to every new franchise restaurant that they opened. Offering his services to the McDonald Brothers, who were looking for a new franchising agent, he took on the job to widen their business. He developed an assembly-line format to prepare food. Through next ensuring years, Kroc eventually became frustrated with the brothers' unwillingness to start their chain with wider marketing of restaurants. Thus in 1961, the $2.7 million that Kroc paid for the McDonald Brothers Corporation, is considered to be one of the greatest acts of salesmanship of all time. From there, he started franchisees nationwide, set strict rules for his franchisees on how the food was to be made, portion sizes, cooking methods, times and packaging. He also let the franchisees decide their best approach to marketing the products in their given locations, which resulted into the most successful fast-food operation in the world to date. As a pioneer in the fast-food industry, he has been called "fast food's founding father." In 1974, he bought the Major League San Diego Padres baseball club and owned the team until his death from heart failure at age 81. Selling hamburgers with fries in a bag, his McDonald's fast-food empire was worth $600 million at the time of his death.