Patterson's Army (the Department of Pennsylvania). Though the regiment had initially been thrilled at the news of its movement, it quickly found guarding the railroad monotonous, and desired action. The regiment did not train as a unit while guarding the railroad due to its dispersed positions, although Companies I and K conducted daily drill. At the end of its term of service, the regiment was mustered out at Harrisburg on 5 August; it had suffered no losses during it service. Major Alexander Hays of the regiment eventually became a brigadier general and was killed at the Battle of the Wilderness, one of many officers and men of the regiment who saw further service in the Union Army during the war. Notable personnel Regimental quartermaster James A. Ekin became a brevet brigadier general by the end of the war and served on the military tribunal that tried the Lincoln assassination conspirators. Private George K. Brady became an officer in the Regular Army and fought in the American Indian Wars. Private Charles Oliver of Company G later reenlisted in the 100th Pennsylvania Infantry and was awarded the Medal of Honor for his actions at the Battle of Fort Stedman in 1865, having served through most of the war. Company K Private Samuel Baldwin Marks Young served through the war as an officer and joined the Regular Army, ultimately becoming the first Chief of Staff of the United States Army. Another Company K Private, Joseph Barr Kiddoo, became an officer and rose to brevet brigadier general by the end of the war. Private Robert Patterson Hughes of Company E also joined the Regular Army postwar, holding command positions in the Philippine–American War. Jonas R. McClintock, the 8th mayor of Pittsburgh was the first captain of the Duquesne Grays. See also List of Pennsylvania Civil War regiments Pennsylvania in the Civil War References Citations Bibliography External links 12th Pennsylvania Rosters (Originals) Military units and formations established in 1861 Military units and formations disestablished in 1861 Units and formations of the Union Army from Pennsylvania