In February 1862 , Dahlgren recommended that the first 13 cast at Fort Pitt be withdrawn because the iron was inferior .
They were cast at the Fort Pitt Foundry and the Washington Navy Yard .
In February 1862 , Dahlgren recommended that the first 13 cast at Fort Pitt Foundry   be withdrawn because the iron was inferior .
They were cast at the Fort Pitt Foundry and the Washington Navy Yard .