All of my ancestors were Southerners. Some were slave holders, some not. Some of their kinfolk moved to Indiana and Illinois in part because of their religious objections to slavery. None of my ancestors made this move although some had similar religious objections.
They all supported the Confederacy in one form or another with most of the adult males serving in uniform. They believed in the cause as their contemporary writings make clear. The cause in which they believed was the preservation of the institution of slavery. Their words are quite unambiguous. Archives are full of letters with similar sentiments and the debates and proclamations of the various state legislatures do not mince words. These documents are both in archives and in print, with much available in electronic form.
You can deny it all you want, but the opinions of Southerners circa 1860 carry more weight than current day ideas of folks who want to paper over an obvious historical fact IMO.
Please post them, I would like to see them.