Horizon blue garrison cap with gold cord trim. The French army wore caps like this during World War I. When the war began, the French wore uniforms comprised of bright red pants and dark blue coats. Because the uniforms were highly visible on the battlefield, the army switched to horizon blue. Its creators thought the color would make soldiers less visible against the skyline or horizon. The "13" on the cap indicates that the wearer was a member of the 13th Army Corps, part of the First Army of France. James C. Hughes of Topeka, Kansas, acquired the cap while serving in France in 1918. Born in Topeka, Kansas, in 1888, Hughes served in the Mexican Border Conflict, World War I, and World War II.