20inch x 30inch Poster Uncle Sam pleads on this poster with America to help the horse. At the time the horse was a military necessity and the tank of its era. This is a poster by James Montgomery Flagg (1877 ?? 1960). He an American artist and illustrator famous for his war effort posters. He also did work for magazines, cartoons, and even paintings Uncle Sam, three-quarter length portrait, standing, facing front, with horse. There is a border around the image. The image size is correct.