Calm and green now, the triple-arched stone span of Burnside Bridge at Antietam Battlefield belies the fury of September 17, 1862 — the bloodiest single day in American history — when Union forces under Maj. Gen. Ambrose E. Burnside stormed across this narrow crossing over Antietam Creek near Sharpsburg, Maryland, while Confederate sharpshooters held them at terrible cost. This chrome-era color postcard captures the bridge in peacetime serenity: leafy trees overhanging quiet water, the masonry arch reflected in the green surface. The reverse carries a detailed historical caption and the intriguing imprint "Another historic scene from the area served by The Potomac Edison System" — a utility company using Civil War heritage in its regional promotional postcard program. Unused and clean, it is a vivid souvenir of one of the Civil War's most pivotal engagements.