On this day in 1864, Confederate General John Chambliss is killed during a cavalry charge at Deep Bottom, Virginia, one of the sieges of Petersburg.
Union General Ulysses S. Grant had bottled the army of Confederate General Robert E. Lee behind a perimeter that stretched from Petersburg to the Confederate capital at Richmond, Virginia, 20 miles north. By June 1864, the armies had settled into trench warfare, with little movement of the lines. In August, Grant sought to break the stalemate by attacking the Southern defenses near Richmond.
In an attempt to regain control of a section of trenches breached by the Yankees, the Confederates counter-attacked, and Chambliss was killed. His body was recovered by a former West Point classmate, Union General David Gregg, who made a surprising discovery: a detailed map of the Richmond defenses. Gregg gave the plan to Union topographical engineers, who then looked for a way to copy and distribute the map through the army's command structure. Using a new photographic technique known as Margedant's Quick Method, which did not require a camera, the engineers traced Chambliss's map and laid it over a sheet of photographic paper. The paper was then exposed to the sun's rays, which darkened the paper except under the traced lines.
The result was a mass-produced negative of the map, which was distributed to all Union officers in the area within 48 hours. It may not have helped the Union capture Richmond--that would take another seven months--but it may have reduced casualties by preventing foolhardy attacks on well-defended positions.