On the March/April 1864 roll, Pvt. Duncan was absent April 27th in Elbert County. The May/June roll had him present. He was captured on June 11, 1864 during the Battle of Trevillian Station, Va. In addition, his horse, saddle, sabre, and bridle were captured.
Pvt. Oliver Duncan was sent to Fortress Monroe, Va. The next record showed that he was exchanged on February 13, 1865. He appeared on a roll of paroled and exchanged prisoners at Camp Lee, near Richmond, Va.