In 1854 an assistant surgeon named Albert J. Myer entered the Union Army and created a system of transmitting information that would revolutionize military communications. His flag-and-torch system led to the formation of the U.S. Army Signal Corps. Major Myer selected only educated men for this new arm of the military, and among these was twenty-three-year-old Louis R. Fortescue. Fortescues memoir, written in the postwar years but based on his wartime diaries, offers a rare view of this lesser-known support arm of the Union army.