Yes, the confederates were complaining about more than just slavery, but slavery was central to secession. In the examples you gave it’s still all about slavery. I think looking at foundational documents and speeches makes it clear that the cause was as simple as “slavery”.
Have you read the declaration of secession?
https://avalon.law.yale.edu/19th_century/csa_scarsec.asp
Or the Cornerstone Speech?
https://en.m.wikipedia.org/wiki/Cornerstone_Speech
Yes, the confederates were complaining about more than just slavery, but slavery was central to secession. In the examples you gave it’s still all about slavery. I think looking at foundational documents and speeches makes it clear that the cause was as simple as “slavery”.
deleted by creator