ANDREW ATKINSON HUMPHREYS - (1810-1883) - Army Engineer, born Philadelphia. Graduated at West Point (1831) and served in Seminole Campaign (1835). Resigned his commission (1856), was employed by government as civil engineer. Rejoined corps of topographical engineers (1838), made survey of delta of Mississippi (1850-51) and of railroad route from Mississippi in Pacific (1854-55). Resumed his work in Mississippi delta (1857), with Lt. Henry L. Abbot compiled A Report on the physics and hydraulics of the Mississippi River(1861), which was basis for subsequent work to control floods and improve river navigation. With outbreak of Civil War,was appointed chief topographical engineer of Army of the Potomac, and after fighting at Fredericksburg, Chancellorsville and Gettysburg, became chief of staff of Army of the Potomac (1863-64). During last stages of War, commanded 2nd Corps under Grant. Chief of Engineers (1866-79). Wrote The Virginia Campaigns of 1864 and 1865 (1882) and From Gettysburg to the Rapidan (1882).