Slavery ended in the the North-why not the south?

The entire economic system of the south was based on slave labor. Large numbers of laborers were needed to grow the crops. Northern industry did not lend itself to this kind of workforce. By the mid nineteenth century, early slaves and indentured servants in the north had gained freedom. Indentures were agreements of a sort of slavery for a limited time during which the laborer worked off his or her indenture. Many household slaves were liberated when the owners either died or retired.