Thomas Jonathan "Stonewall" Jackson (January 21, 1824 – May 10, 1863) was a Confederate general during the American Civil War, and probably the most well-known Confederate commander after General Robert E. Lee. His military career includes the Valley Campaign of 1862 and his service as a corps commander in the Army of Northern Virginia under Robert E. Lee. Confederate pickets accidentally shot him at the Battle of Chancellorsville on May 2, 1863, which the general survived, albeit with the loss of an arm to amputation. However, he died of complications of pneumonia eight days later. His death was a severe setback for the Confederacy, affecting not only its military prospects, but also the morale of its army and of the general public. Military historians consider Jackson to be one of the most gifted tactical commanders in United States history. His Valley Campaign and his of the Union Army right wing at Chancellorsville are studied worldwide even today as examples of innovative and bold leadership. He excelled as well in other battles: the First Battle of Bull Run (where he received his famous nickname "Stonewall"), the Second Battle of Bull Run, Antietam, and Fredericksburg. Jackson was not universally successful as a commander, however, as displayed by his weak and confused efforts during the Seven Days Battles around Richmond in 1862.