In 1864-65 he commanded the steamer of the North Atlantic Blockading Squadron. "Sassacus" towed the powder boat from Norfolk to Fort Fisher in December, and was engaged during the First and Second Battles of Fort Fisher in December 1864 and January 1865. Davis also took part in attacks on Fort Anderson on the Cape Fear River on 18 February; and on Fort Strong on 20 and 21 February. His ship was struck under the waterline, but the leak was kept under control until dark, and then effectually stopped.