1 million lives were sacrificed, but think about all of the lives that were saved because slavery was outlawed by Lincoln. If the civil war did not happen, countless lives would have continued to suffer or perish because of slavery. If Lincoln did not outlaw it, someone was bound to later on, but for all we know, 2 or 3 million lives could have been sacrificed in that war. Also, if this divide about slavery continued between the states, the southern states may have completed left our nation considering the disagreement had been perpetuated for even longer and had been more engrained.

Hypotheticals exist for nearly every situation, good and bad. We can not guarantee anything. However, I think the civil war was a price to pay for slavery to be abolished sooner and possibly more amicably than otherwise.