Waist-up carte-de-visite portrait of Brigadier General Henry Hays Lockwood. In May 1861, with the outbreak of the Civil War, the governor of Delaware appointed Lockwood as the colonel of the 1st Delaware Infantry. By August 1861, he was appointed to brigadier-general of . He was in action during the Battle of Gettysburg. After the battle, he was appointed garrison commander at Harper's Ferry and was eventually appointed commander of the Middle Department at Baltimore, Maryland. After the war he became a professor of mathematics at the U.S. Naval Academy at Annapolis, Maryland.