Dad's Root Beer was developed in the 1930s by partners Barney Berns and Ely Klapman in the basement of Klapman's Chicago-area home. The first trademark registration was filed on September 24, 1938, granted on February 14, 1939, to the Dad's Root Beer Company of Chicago, with the product name in use since February 1937. Dad's earned a loyal following. Dad's Root Beer brand was famous throughout the Midwest and by the late 1940s, was one of the most consumed brands of root beer throughout the United States. Jules Klapman, son of co-founder Ely, successfully took the Dad's brand international. The name Dad's Old Fashioned Root Beer was selected in honor of Ely Klapman's father, and other fathers, who used to make root beer at home for their families (popular in the early 20th century).