During the 1850s, arguments raged over the morality of slave-holding, and the exegesis of Scripture played a key role in those debates. The exegetical battles were one-sided: all abolitionists could point to was Galatians 3:28 and the Letter of Philemon, while slave owners had the rest of the Old and New Testaments, which gave every indication that slave holding was a legitimate, indeed God-ordained social arrangement, one to which neither Moses nor Jesus nor Paul raised a fundamental objection. So how is it that now, in the early twenty-first century, the authority of the scriptural texts on slavery and the arguments made on their basis appear to all of us, without exception, as completely beside the point and deeply wrong?
The answer is that over time the human experience of slavery and its horror came home to the popular conscience—through personal testimony and direct personal contact, through fiction like Uncle Tom’s Cabin, and, of course, through a great Civil War in which ghastly numbers of people gave their lives so that slaves could be seen not as property but as persons. As persons, they could be treated by the same law of love that governed relations among all Christians and could therefore eventually also realize full civil rights within society. And once that experience of their full humanity and the evil of their bondage reached a stage of critical consciousness, this nation could neither turn back to the practice of slavery nor ever read the Bible in the same way again.
Luke T Johnson, emeritus Woodruff Professor of New Testament and Christian Origins at the Candler School of Theology, Emory University,

(I’m interested in “nor ever read the Bible in the same way again.” He’s implying southerners read it wrong once; we can do so and perhaps are doing so again. What say you?)