The United States possessed no combat-worthy aircraft upon entry into World War I in 1917. Several European aircraft were considered. The British DH-4 was selected because of its comparatively simple construction and its apparent adaptability to mass production. It was also well-suited to the new American 400-horsepower Liberty V-12 engine. American-built DH-4s were dubbed the "Liberty Plane." Highlighted in this image are a vertical stabilizer and tail of the De Havilland DH-4.