Don't necessarily agree, but then again I am from the south (although Native American) and have looked at the causes of the Civil War. The greed of the north is always ignored when northerners discuss this topic. If the south had industrialized machinery to accomplish the work, there still would have been a war. It was over money and power. Slavery was used as the ruse to get the backing of the people.
Personally, I believe a greater mistake was made in the genocide against the First Nations on this continent. Without them fighting against the English in the Revolutionary War for independence, you might still be bowing to Her Majesty in Great Brittain.
The Cherokee gave many lives in fighting with Andrew Jackson against the Creek. Junaluska brought 500 of his warriors to the fight and even risked his own life to save Andrew Jackson's life from a Creek who was about to slay him. What was their reward? The Trail of Tears.
Many Cherokee I know today still will not accept a $20 bill in payment for anything --- because it bears HIS picture.