Civil War Union Army Officer. He was mustered in as Captain and commander of Company D, 26th New York Volunteer Infantry on May 21, 1861, and served with his unit August 1862, when he was transferred to the United States Army Adjutant General department. He served as an Assistant Adjutant General until November 1862, when he resigned from that department to accept a commission of Lieutenant Colonel of the 157th New York Volunteer Infantry. On the eve of the Battle of Gettysburg he was taken sick, but opted to stay with his men, despite the objections of his regimental surgeon. On the first day of the battle (July 1, 1863) the 157th New York was defending the XI Corps line north of the town when Lieutenant Colonel Arrowsmith was shot in the forehead. Taken unconscious to a field hospital, he died a few hours later. His body was recovered after the battle by his brother, and he was interred in his family plot.
Bio by: RPD2