Clarification/Follow-up by tomder55 on 03/12/07 1:15 pm:
After the death of Jackson Lee reorganized his army into 3 corps from the 2 commanded by Jackson and Lt. Gen. James Longstreet. The 3 new divisions were commanded by Longstreet ;Lieutenant General Richard S. Ewell ,and Lt. Gen. A.P. Hill, one of Jackson's division commanders .Jackson's replacement Lieutenant General Richard S. Ewell was not as capable commander. This was evident on the 1st day of Gettysburg when he could've taken Culp's Hill and secured the high ground .
Lee had sent vague messages to Ewell that the hill should be taken("if practicable." ) that frankly Jackson would've recognized without instructions .Ewell chose instead not to attempt the assault .The battlefield was thus shaped in favor of the Union Army. When Ewell's corps did attack these positions on July 2 and July 3, the Union had had time to fully occupy the heights and build impregnable defenses.

On day 2 of the battle Lee put the bulk of the action on the back of Longstreet's corp . They assaulted the left flank of the Union lines and damn near acheived their objective .Consider that the 20th Maine held Little Round Top and repelled repeated assaults by from General Law's Brigade .Running out of ammo ,Chamberlain ordered a bayonet charge by his depleted ranks .That charge broke the Confederate assault and the effort to take the Union flank stalled.

General Lee was alone responsible for the debacle on day 3 and indirectly for not seizing the high ground on day # 1 . He knew that 2/3 of his forces were being commanded by different Generals and should've made his desires clearer to Ewell. He also ignored the advice of the cautious Longstreet who was correct in his advice to not assault the Union center on day 3 .It is the pervue of 2nd guessers to speculate how things would've gone different however . Lee had a reasonable belief that the gamble of the invasion of the North would end the war favorable to the South . He also realized that the South's resources were depleting and the invasion of the North was the equivalent of the 'hail Mary 'pass ....not likely to succeede but an attempt that has to be tried. The bottom line is that the South was going to lose the war whether or not Jackson survived.