Washington City: Defenses Surrounding the City

By the close of the Civil War, Washington, D.C. was the most heavily fortified city in North America, perhaps even in the world. According to the report of the army’s official engineer, her defenses boasted 68 enclosed forts with 807 mounted cannon and 93 mortars, 93 unarmed batteries with 401 emplacements for field guns and 20 miles of rifle trenches plus three blockhouses.