The north did indeed want to free blacks and were willing to fight the Civil War to do it but not necessarily to make blacks any better off but, as it turned out, to free up a very large, lucrative and mobile labor pool. Once the slaves were free of southern aristocratic plantation owners the men could be delivered into northern owned steel, limestone, timber and real estate development operations (road building) throughout the South via sheriffs, judges, labor brokers. The “freed” black was still enslaved in the south but now working for Northern owned interests. This was a classic Marxian re-distribution of an inefficient labor force. Such economy-based redistributions are at the root of all revolutions according to Marxist theory.See: Slavery By Another Name - Blackmun