The slave owners in the south supported slavery because slaves used to work very hard and that too in less money.
Step-by-step explanation:
The people in the southern region of the United States of America were in favor of the slavery and did not want it to end. The reason for this is that they found slaves for working in their plantations.
These slaves used to work for very less money which turned out to be very lucrative and profitable for the slave owners, increasing the production because the slaves used to work very hard.