The U.S.S Sebago (1862-1867), first of a class of two 1070-ton 'double-ender' steam gunboats built at the Portsmouth Navy Yard, Kittery, Maine, was commissioned in March 1862. Her first three months of active service were spent in area of Hampton Roads and the nearby York and James Rivers in Virginia, supporting the General McClellan's unsuccessful campaign to take the Confederate capital at Richmond. Sebago was sent to join the blockade off Charleston, South Carolina, in July 1862, and remained in that vicinity until she was damaged by grounding in June 1863. Following an overhaul at New York, in December 1863 Sebago was assigned to the West Gulf Blockading Squadron. She served in the Gulf of Mexico until the end of the Civil War. During the August 5, 1864 Battle of Mobile Bay, the gunboat provided support from outside the Bay as Rear Admiral Farragut fought his ships past Fort Morgan to close the South's principal remaining Gulf seaport. When the war ended, Sebago was decommissioned in July 1865 and sold in January 1867.