 Meantime he had been promoted, November 17, 1862, to the rank of Major, July 30, 1863, to that of Lieutenant Colonel, and October 16, 1863 to that of Colonel.On January 1, 1864 at Nashville, Tennessee he was transferred as Colonel to the First Regiment of Engineers Missouri Volunteers, a new regiment formed by the consolidation of the former engineer regiment and the Twenty fifth Missouri Infantry.During the summer of 1864 he was engaged in completing the Nashville and Northwestern Rail road from Nashville to Johnsonville and in constructing defensive works.