The dismal performance of Ewell and Hill raises the question: would things have been different for the Confederacy at Gettysburg had “Stonewall” Jackson not been mortally wounded at Chancellorsville a month and a half earlier? On the surface, it seems that Jackson’s presence would have made a difference. One cannot imagine Jackson deciding not to continue the attack on July 1, as Ewell did.
Remember that during the first day of battle, Lee had shattered two Union corps, the I and XI, inflicting 9,000 casualties, including 3,000 captured. Although the Union position on Cemetery and Culp’s Hills was strong, the soldiers of the shattered corps were demoralized. Had Ewell proven as aggressive as Jackson, it is likely that the Confederates would have carried the Federal position on the evening of July 1. Lee would thereby have achieved his vision of defeating the Union army piecemeal before it could concentrate on the field of battle, driving one corps back on another and creating panic. Nor can one imagine Jackson permitting the echelon attack to break down on July 2 as Hill did.
But there is a second question: which Jackson would it have been: the aggressive Jackson of the Valley, Second Manassas, and Chancellorsville; or the lethargic Jackson of the Seven Days Battles on the Virginia Peninsula in June of 1862? As the latter example proves, Jackson was not super-human. During the Seven Days, he succumbed to physical exhaustion, which affected his performance. This was likely the case with Hill at Gettysburg. This extremely aggressive leader was ill during the battle and accordingly did not push his troops the way Lee expected. As the example of the Seven Days indicates, a sick or exhausted Jackson would not have performed any better than Ewell or Hill.