The Federal Signal Service at Antietam

This book restores to view a forgotten but essential arm of the Union war effort. On September 17, 1862, while the bloodiest single day in American history raged at Antietam, a network of young officers with flags and telescopes linked staff headquarters, high-ground observation posts, and forward stations close to the fighting, furnishing Major General George B. McClellan with near real-time intelligence on Confederate movements. Their constant signaling disproves the enduring "spectator general" myth and reveals how signal communications informed command decisions. Drawing on a wealth of primary sources, the author combines operational analysis with vivid biographical portraits of the men who carried out this overlooked but crucial work. This deeply researched study shows that the Federal Signal Service's role was far from that of an anonymous adjunct but rather was vital to command and control in the Maryland Campaign.