I’m southern and I have the family Bible from the 1823 where handwritten notes from then through the war stated distaste of slavery. For one, the slaves were cheap labor, taking jobs the poor southerners desired.
Then how do you explain the Confederate Constitution?
Most people think that Northerners opposed slavery because they thought it was immoral and that they cared about black people. After much research on the subject, it becomes clear that Northerners did not give a crap about black people, and only hated slavery because they saw it as a threat to white men earning wages.
They hated slavery because it undermined efforts of people to sell their labor for income, but people telling the story nowadays would have us believe most Northerners were motivated by morality, and this is simply not true at all.
Some were, but they were a small minority, and at the time regarded as liberal kooks, while the vast majority of the population simply ignored them.