What was the south advantages of the south for the Battle of Gettysburg?

Answer 1

One of the primary advantages was the style of battle that the southern troops chose. They marched across the battlefield in square formation without cover and from lower ground than the northern troops. This approach made them - essentially - sitting ducks and a battle that had been fairly balanced up to this point suddenly became very one sided as a large portion of the Confederate forces were wiped out at this point. (Battle Cry of Freedom - McPherson)

Lee had little choice, if he was bent on attack. The Union held the high ground with superior numbers. Any attack in force would have been suicidal.

Answer 2

Their only advantage was their commander, and Lee did not perform at his best. He allowed the enemy to seize the high ground. He was unable to maneuver around to their flanks. His frontal assaults against their prepared positions and superior numbers seemed doomed from the start.