 Kroc and Sonneborn had a falling-out over expansion of McDonalds and Sonneborn resigned in 1967; Kroc took over the title of CEO and president.In 1968 the now legendary Big Mac made its debut, and in 1969 McDonald's sold its five billionth hamburger.Two years later, as it launched the "You Deserve a Break Today" advertising campaign, McDonald's restaurants had reached all 50 states.