What did Slave owning states believe about state's rights?

The slave owning states believed about the states' rights that the federal government should not intervene in the rights of the southern states regarding the ownership of slaves.

Explanation:

The states in the southern United States had their economies based on the agriculture they carried out at the hands of slaves. The leaderships of these states feared that if the slaves are granted the status of free men, the economy of their states would crumble and eventually make most noble families, including that of the leaders themselves, in these states bankrupt.