Why did Southerners argue states rights were violated by evolution of slavery?

Southerners argued that states' rights were violated by the evolution of slavery because they believed that individual states should have the authority to determine their own laws regarding slavery without federal intervention. They viewed federal actions aimed at restricting or abolishing slavery as an infringement on their sovereignty and autonomy. This perspective was rooted in a commitment to the Constitution, which they interpreted as allowing for the protection of their economic and social systems based on slave labor. Consequently, they framed the debate as a matter of preserving their rights as states against what they perceived as overreach by the federal government.