DUANE, James Chatham, military engineer, born in Schenectady, New York, 30 June 1824. He was graduated at Union College in 1844, and at the U. S. military academy in 1848. From 1848 till 1854 he served with the engineer corps, and as assistant instructor at West Point. He was then employed in the construction of fortifications till 1856, was lighthouse inspector at New York in 1856'8, commanded the engineer company in the Utah expedition of 1858, and was afterward instructor of engineering at the military academy till the beginning of the civil war. He was stationed at Fort Pickens, Fla., in 1861. During the winter following he organized engineer equipage for the Army of the Potomac, went to Harper's Ferry in February 1862, to bridge the Potomac commanded the engineer battalion at the siege of Yorktown, constructed bridges across Chickahominy and White Oak swamps, was engaged at Gaines's Mill on 27 June 1862, and in the subsequent operations of the Peninsular campaign made roads, fieldworks, and bridges, notably one 2,000 feet long across the Chickahominy.

In the Maryland campaign he served as chief engineer of the Army of the Potomac, and was engaged at South Mountain and Antietam. In 1863, as chief engineer of the Department of the South, he took part in the attack on Fort McAllister, Georgia, and in operations against Charleston. From 15 July 1863, he was again attached to the Army of the Potomac, and was engaged at Manassas Gap, Rappahannock Station, the Wilderness, and Cold Harbor, and distinguished himself at the siege of Petersburg. He became captain of engineers on 6 August 1861, major on 3 March 1863, and was brevetted colonel on 6 July 1864, and brigadier general at the close of the war. >From 1865 to 1868 he superintended the construction of the fort at Willet's Point, New York, receiving promotion as lieutenant colonel on 7 March 1867. He served subsequently as superintendent of fortifications on the coast of Maine and New Hampshire, as lighthouse engineer of the northeast coast, as a member of various engineer boards, and as president of the board of engineers in New York City. He was promoted colonel on 10 January 1883, and in the autumn of 1886 was appointed chief of engineers, with the rank of brigadier general. He has published a "Manual for Engineer Troops" (New York, 1862).