Civil War Union Brevet Brigadier General. As a commander in the New York City Militia, he was recruited under special authority from the War Department to organize a regiment at the outbreak of the Civil War. In September 1861, he was commissioned Colonel in command of the 69th Regiment New York Volunteer Infantry and left the state to join the Army of the Potomac. He with the 69th participated in, the Battle of Gettysburg, Fredericksburg, the Spotsylvania, the Petersburg Campaigns and the road to Appomattox Court House. For distingished leadership of the 69th Regiment, he was brevetted Brevet Brigadier General of U.S. Volunteers on March 13, 1865. After the 69th was honorably discharged and mustered out on June 30, 1865, he remained in the Regular Army at the rank of Major on the staff of the Provost Marshal General.