One of its other major objections is that New York (well within its rights) had begun to forbid slaveholders to bring slaves within New York State borders. Again, a slavery issue, not states' rights.
Another objection? Some of New England allowed black men to vote, and didn't outlaw abolitionist societies. Again, something that New England states are well within their rights to do, and that does not infringe upon southern states' rights.
Mississippi's secession declaration of 1861? "Our position is thoroughly identified with the institution of slavery — the greatest material interest of the world"
Another few words from Lincoln to close off:
“If I could save the Union without freeing any slave, I would do it; and if I could save it by freeing all the slaves, I would do it; and if I could save it by freeing some and leaving others alone, I would also do that. What I do about slavery and the colored race, I do because I believe it helps to save the Union; and what I forbear, I forbear because I do not believe it would help to save the Union... I have here stated my purpose according to my view of official duty; and I intend no modification of my oft-expressed personal wish that all men every where could be free”