He was the son of Martha Kingsley and Daniel McNeill; he was AMW's brother. He married Maria Matilda Camman on 13 June 1821.
He graduated from the USMA, West Point, NY in 1817, and served on topographical duty in the engineer corps from 1817 to 1823. He was promoted 2nd lieutenant of artillery on 1 March 1818, 1st lieutenant in 1819, and 1st lieutenant in the 1st Artillery on the reorganization of the army in 1821. He served on the survey of the Chesapeake and Ohio canal, 1824-26; the Kanawha, James and Roanoke rivers in Virginia in 1827; the Baltimore and Ohio railroad in 1827 and was a member of the board of civil engineers during the construction of the road, 1827-30. In November 1828, with George W. Whistler and Jonathan Knight, he was sent by the Baltimore and Ohio Railroad Company to study the railroad system in Great Britain. He was chief engineer of many railroads including Baltimore and Susquehanna railroad, 1830-36, Paterson and Hudson River railroad, NJ, 1831-34; and Boston and Providence railroad, 1832-35; Providence and Stonington, 1832-37. He was brevetted Major in 1833, but resigned from the US army in 1837, to become chief engineer of the state of Georgia, and he surveyed the route for a railroad from Charleston, SC, to Louisville, KY, and thence to Cincinnati, Ohio, 1837-40. He was president of the Chesapeake and Ohio Canal company, 1842-43. He was chief-engineer of the Brooklyn navy yard dry dock, 1842-45. He was made a member of the Institution of Civil Engineers of London, 4 May 1852; the first American to be so honoured.
Johnson, Rossiter (ed.), The Twentieth Century Biographical Dictionary of Notable Americans, 10 vols., Boston, 1904, vol. 7.