Who is "our enemy?" The confederates were all Americans. They certainly weren't my enemy.
Confederates were not Americans when they fought the Civil War. They renounced their citizenship and became citizens of the Confederacy. They quit their country and formed a new one. They were the enemy of the United States. Once they were defeated and the Confederacy ceased to exist, they were allowed to come back into the Union as citizens. And ofcourse they weren't your enemy, you weren't alive when all this occured.