Barnes graduated from the USMA, West Point, NY in 1829, and served as assistant instructor there 1829-30. He was promoted lieutenant of artillery and participated in the Black Hawk expedition. He was an assistant instructor at USMA, 1833-36, resigned from the army in 1836, and became a railroad engineer. He was commissioned colonel of volunteers in the Union army in 1861 and brigadier-general of volunteers in 1862. He was an old friend of AMW and her husband from their Springfield years (1840-1842).
Johnson, Rossiter (ed.), The Twentieth Century Biographical Dictionary of Notable Americans, 10 vols., Boston, 1904, vol. 1; Who Was Who in America, Chicago, 1963, p. 41.