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

Southerners argued that the abolition of slavery violated states' rights because they believed that each state had the authority to determine its own laws and governance, including the legality of slavery. They contended that the federal government overstepped its constitutional boundaries by interfering in what they viewed as a state matter. This perspective was rooted in a broader belief in the sovereignty of states and a resistance to federal authority. Thus, they framed the abolition of slavery as an infringement on their rights and autonomy as states.