Recommissioned on July 20, 1864, the "Susquehanna" was assigned to the North Atlantic Blockading Squadron and participated in the First Battle on Fort Fisher, on Christmas Eve 1864. Near the end of the American Civil War, on January 13, 1865, the United States Navy admiral, David Dixon Porter shifted fire to Fort Fisher itself. On January 17th, in the successful assault and capture, by the Union Army, Navy and Marine Corps at the second battle of Fort Fisher south of Wilmington, North Carolina, the U.S. frigate "Susquehanna" was under command of Rear Admiral Sylvanus William Godon. Gordan said that "James Callahan, coast pilot, whom I at all times found most servicable." During the attack at Fort Fisher, Callahan was at the helm of the "Susquehanna" maneuvered the vessel to protect the crew from injury and guided the ship safely into port. The battle closed Wilmington, North Carolina, the Confederate States's last major port.