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Captain William C. Margedant, a native of Prussia who later worked as an architect and engineer in Cincinnati, Ohio, made a significant but relatively unsung contribution to military cartography during the American Civil War. His tenure as the chief topographical engineer for Major General William S. Rosecrans, particularly during the Tullahoma Campaign in June and July of 1863, was marked by a key innovation in the field of map duplication.

Margedant's military service commenced with the 10th Ohio Infantry. His notable contribution emerged during his early wartime service in Western Virginia, where he invented a method for rapidly duplicating maps. This method, which he devised out of necessity, involved a "photo-printing device" that used a light box with chemically treated India rubber baths. The process included tracing maps onto thin tissue paper, overlaying it on photographic paper treated with nitrate of silver, and then exposing it to sunlight. This produced a negative copy, highlighting critical features like roads and rivers in white against a dark background.

This innovation, while simple, was crucial for the Union Army. By 1863, Margedant and his team efficiently integrated daily updates from other topographical engineers into a master map. These updates facilitated the nightly distribution of current maps to various military units, including corps, divisions, brigades, and individual regiments. The maps, often assembled on canvas or cloth and varnished for durability, became essential tools for commanders.

Margedant's work, though not widely celebrated, provided a tangible benefit to the Union forces. The ability to rapidly produce and disseminate accurate maps was a significant aid in the planning and execution of military operations, including the Tullahoma Campaign. The technology he developed was a practical solution to a pressing need in wartime conditions, reflecting the importance of innovation in military strategy and logistics.


Archived

Place/Date:
[Chattanooga, Tennessee] / 1864 circa (probably late spring or early summer)
Size:
13 x 20 inches
Condition:
Good
Stock#:
66727