DENNIS HART MAHAN - (1802-1871) - Army Engineer, born New York City. Graduated at West Point (1824), taught engineering while attending and after graduating, studied engineering in Europe (1826-30), attached to the military school of engineers and artillery at Metz, France the last year. Assistant professor and then professor of engineer at West Point (1830-71) being dean of the faculty (1838-71). Appointed by Governor Floyd of Virginia to determind route of the Baltimore and Ohio Railroad (1850) and elected overseer of the Thayer School of Civil Engineering (1871). A member of the Geographical Society of France, an original incorporator of the National Academy of Sciences and a member of many learned societies. Author of many engineering books.