The point that you cannot grasp is at the time there was no law against slavery. It was perfectly legal. It was also covered many times in the Bible, both New Testament and Old and never was it prohibited but it concerned how one treated his or her slaves, not whether one owned slaves or not.
Lincoln, instead of preserving the union, in the long run, as evidenced by the status quo, destroyed the union.
"I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man." Thomas Jefferson
