[terminalshort]

This is not true at all. Slavery wasn't allowed in the rural north. And in the south, slavery was part of all sectors of the economy. Slave factories were even a thing. Furthermore, slave labor could be traded on the market just as well as any other labor. There was nothing stopping a slave owner from renting out his slaves a contract labor. If the civil war hadn't happened when it did, southern slavery would have been an industrial horror.