In December the unit was assigned to the newly formed XXV Corps and took part in the failed attack on Fort Fisher, North Carolina, from December 7 to December 27, 1864, and the successful Second Battle of Fort Fisher from January 7 to January 15, 1865, including the bombardment of the fort starting on the 13th and the final assault and capture on the 15th. The 6th then saw action at Sugar Loaf Hill on January 19 and at Sugar Loaf Battery on February 11 before taking part in the Battle of Wilmington at Fort Anderson from February 18 to February 20 and the capture of Wilmington as well as action at Northeast Ferry on February 22, 1865.