Fort Pitt Foundry also made 16 for the army in 1861 .
IX - inch Dahlgren shell gun : 1,185 guns were cast at Alger , Bellona , Fort Pitt , Seyfert , McManus & Co. , Tredegar , and West Point foundries between 1855 and 1864 .
Fort Pitt     also made 16 for the army in 1861 .
IX - inch Dahlgren shell gun : 1,185 guns were cast at Alger , Bellona , Fort Pitt , Seyfert , McManus & Co. , Tredegar , and West Point foundries between 1855 and 1864 .