Pittsburgh in the American Civil War

Pittsburgh, Pennsylvania was a thriving and important city during the American Civil War, and provided a significant source of personnel, war materiel, armament, ammunition, and supplies to the Union Army. Situated at the confluence of the Monongahela, Allegheny and Ohio rivers, Pittsburgh was an important transportation hub for both riverine and rail transport, as well as overland via its system of roads.

The antebellum iron industry in Pittsburgh had thrived, fueled by access to coal, iron ore, and other raw materials, as well as transportation routes to get the iron to markets. In 1859, the Clinton and Soho iron furnaces introduced coke-fired smelting to the region. Within three years, the growing needs of the military effort during the Civil War had boosted the city's economy with increased production of iron and armaments, especially at the Allegheny Arsenal and the Fort Pitt Foundry. Arms manufacture included ironclad warships and the world's first 21" heavy artillery gun. By war's end, over one-half of the steel and more than one-third of all U.S. glass was produced in Pittsburgh.

During the war, Pittsburgh's heavy industry provided significant quantities of weapons and ammunition. The Fort Pitt Foundry made mammoth iron castings for giant siege howitzers and mortars, among the largest guns in the world. One of the largest was a 20-inch bore Rodman Gun, a large black powder, smoothbore, muzzle-loading coastal defense gun. The foundry produced 1,193 guns (15 percent of the total U.S. wartime artillery production) and almost 200,000 artillery projectiles. Other prominent Pittsburgh area factories included Singer, Nimick and Co. (maker of 3" Ordnance rifles) and Smith, Park and Co., which produced more than 300,000 projectiles. Pittsburgh industries collectively manufactured 10 percent of the total U.S. wartime production of artillery rounds.

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