I know you thought you were right. That's why I corrected you, to help balance and rectify the record.
In your opinion.
Call it states rights or second-class citizenship it you want, the underlying issue was slavery and the protection of it at all costs as a viable institution in the U.S. The south, correctly, viewed slavery as the cornerstone of their economic well-being, and the fabric of their southern society. They viewed the election of the Republican administration as a threat to that institution, and as their reason for rebellion.