In August 1864, a large expedition force commanded by Maj. Gen. Gouverneur K. Warren severed the Weldon Railroad, the main supply line for the Confederate army, during the Second Battle of the Weldon Railroad. The 56th Massachusetts had one man killed and nine wounded during this engagement. The regiment remained encamped near the railroad until the end of September. During this time, their division was discontinued due to its severe depletion. The remaining men of the 56th Massachusetts were attached to the Second Brigade, Second Division of the IX Corps.