Fort Johnson, section of map of the defences of Charleston Harbor, South Carolina
Scale 1:1200. LC Civil War Maps (2nd ed.), 386 Below neat line of map: Furnished by the War Department to the City Council of Charleston, S.C. Shows topography by hachures, drainage, vegetation, batteries, and a detailed plan of the fortifications. Description derived from published bibliography. Available also through the Library of Congress web site as raster image.
United States. Army. Corps of Engineers