Wood was initially detached to Elmira, where he worked in draft rendezvous and served as assistant adjutant general of the post. He returned at his own request to his command and regiment in May 1864. He served on General James B. Ricketts' staff in October 1864, and after the general was severely wounded he continued on General Truman Seymour's staff as judge advocate. He returned to his regiment when he was promoted to major. He resigned his commission after the war in May 1865, with the rank of brevet rank of lieutenant colonel. He participated in the Battles of Cold Harbor, Petersburg, Monocacy, Winchester, and Fisher's Hill.