Back then, food franchising was all but unheard of, but the new product's potential made it a natural for such a system. When the United States entered World War II in December 1941, there were less than 10 Dairy Queen stores. However shortly after the war, the system took off at a pace virtually unrivaled before or since. With only 100 stores in 1947, it grew to 1, 446 in 1950 and then to 2,...