[Marat]

The main driving point was the desire to curb the economic and political power of the southern states.
If the economic and political power of the southern states had been allowed to grow unchecked, the northern elite would've lost their power, the USA would've remained a primarily agrarian country and would've lagged behind the UK and Germany in the industrial race. What in the heck? Who in the world are you reading? Yes, the Northern and Southern states had different economic interests, but the reason the South left was because they were afraid that Lincoln would ban slavery. After all, his party, the Republicans came into existance after the Whigs split on North & South lines because of.... get this... slavery! And not just because of cynical interests, but because of honest-to-goodness moral concerns.