Civil War Union Brevet Brigadier General. A newly-minted lawyer when the Civil War began, he helped recruit a company that eventually was mustered into Federal service as Company I, 30th New York Volunteer Infantry. Initially enlisted as a Private, he was elected to be the unit's 2nd Lieutenant, and was commissioned at that rank on June 1, 1861. After serving at that duty for a year, he was promoted to 1st Lieutenant and Regimental Adjutant on May 28, 1862. However, while stationed with the regiment at Falmouth, Virginia, he became afflicted with typhoid fever, and was eventually sent back to New York to convalesce. After recovering, he was appointed by the New York State Governor as Major of the 169th New York Volunteer Infantry (October 5, 1862). A month later he found himself in command of the regiment, which he led in the Union operations around Suffolk, Virginia in May 1863. Wounded in the action there, he remained in command as the unit then saw action in Portsmouth, Virginia and during the Siege of Charleston, South Carolina. Promoted to Lieutenant Colonel on February 13, 1864, he served as second in command to Colonel John McConihe in General Ulysses S. Grant's Spring 1864 Overland Campaign in Virginia. On June 1, 1864 he took part with the 169th New York in the bloody Battle of Cold Harbor, and again assumed command of the regiment when Colonel McConihe was killed. Colonel Alden himself was shot in the head, having reached the Confederate works and planting the Union flag on the parapet just before his wounding. Advanced to full Colonel and official commander of the unit in September 1864 (to date from June 1, 1864), he assumed command of his brigade in the capture of Fort Fisher, North Carolina in January 1865. There he was severely wounded by the explosion of an ammunition magazine and remained in a semi-conscious state for five weeks (newspapers had reported him killed). Still feeling the effects of his wounds (he would have permanent semi-paralysis on his right side for the remainder of his life) he returned to command while still on crutches. He was brevetted Brigadier General, US Volunteers (to date from January 15, 1865), and was honorably mustered out of Federal service on July 19, 1865 at Raleigh, North Carolina. Unable to return to the law profession due to his permanent wounds, he became Postmaster of Troy, New York in 1866.