; born in Lancaster, Pa.
, Sept. 20, 1820; graduated at West Point
in 1841; served through the war with Mexico
; took part in the expedition against the Rogue River
Indians and in the Utah
expedition of 1858; appointed brigadier-general of volunteers in 1861; took part in the battles of Mechanicsville
, Gaines's Mill
, and Glendale
In the last-named battle he was taken prisoner, but was soon exchanged and returned to duty.
He participated in the battle of Bull Run
, and on Nov. 29, 1862, was promoted to the rank of major-general of volunteers, succeeding General Hooker
in command of the 1st Corps of the Army of the Potomac.
On the first day of the battle of Gettysburg
(July 1, 1863), he was in command of the left wing of the National
army, and was shot dead.
A monument in his honor was erected at Gettysburg