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).