Semi-scale model, made by Charles Wesly Crawford and exhibited at the Pittsburgh, Pennsylvania, Sanitary Fair during the Civil War to raise money for the wounded and sick from the front. Photograph by Purviance's Photographers, Pittsburgh. Note models in the background, including sailboats, artillery limbers, and a heavy Rodman-type cannon. Courtesy of Captain G.W. Swartz. U.S. Naval History and Heritage Command Photograph.