Draw between lee and mcclellan
Gives the people in the north a moral purpose for fighting the war instead of one to maintain union. This also removes the possibility of french and british recognition and aid to the south due to the slave issues.
The high point in the war as lee wins all battles. He brings all of his troops up to Gettysburg to end the war by taking putting pressure on washington. Picketts charge is a miserable failure and it is the last time that the confederacy is able to push into the north.