Flagg's depiction of Uncle Sam was shown publicly for the first time, according to some, on the cover of the magazine Leslie's Weekly on July 6, 1916, with the caption "What Are You Doing for Preparedness?"[1][15] More than four million copies of this image were printed between 1917 and 1918. Flagg's image was also used extensively during World War II, during which the US was codenamed "Samland" by the German intelligence agency Abwehr.[16] The term was central in the song "The Yankee Doodle Boy", which was featured in 1942 in the musical Yankee Doodle Dandy.