Through the remainder of the war, ironclads saw action in the Union's attacks on Confederate ports. Seven Union monitors, including , as well as two other ironclads, the ironclad frigate "New Ironsides" and a light-draft , participated in the failed attack on Charleston; one was sunk. Two small ironclads, and participated in the defence of the harbor. For the later attack at Mobile Bay, the Union assembled four monitors as well as 11 wooden ships, facing the , the Confederacy's most powerful ironclad and the gunboats , , .