The son of German pianist and composer Otto Dresel, Ellis Dresel handled the affairs of the U.S. embassy in Vienna after the United States entered the war, and was responsible for relations between the German government and British prisoners of war from 1917 to 1918. During that time, in Berne, Dresel also worked with the American Red Cross, the American Legation, and its War Trade Board. In 1921, his title was changed to chargé d'affaires, and he signed the formal peace treaty. The following year he returned to the United States.