[AVIATION]. Lee Keedick Presents Col. W.A. Bishop / The World?s Greatest Ace. N.p., ca. 1919. Color lithograph poster depicting World War I Canadian flying ace William A. ?Billy? Bishop. 52 ? x 40?. Linen backed. Minor repaired closed tears. A-. As credited on this poster, Bishop downed 72 German airplanes in World War I, making him Canada?s top flying ace. He published Winged Warfare in 1918 and began lecturing in America?s major cities, describing his exploits in the war.