(Part 1)

For purposes of your question the way you’ve worded it, I’m going to focus largely on white abolitionists here, since I think that’s what you’re getting at.

The first thing to address here is a point of terminology that, while well known in the scholarly discussion of this topic, is less widely known in popular treatments. This would be the distinction between abolitionism and anti-slavery. When discussing the Civil War era, the term abolitionism is often reserved for descriptions of individuals or movements who agitated for taking affirmative steps to end slavery. In the 19th century, this was very much a minority viewpoint even in the North. Antislavery more generally refers to groups or individuals who desired a more gradual elimination of slavery, wanted to ameliorate its more negative consequences, or were generally opposed to it, wished to see it stop expanding, or were otherwise ambivalent towards taking steps to end it. This family of positions was much more popular in the mid-19th century North, as it did not require any particular steps, and allowed white northerners to maintain at least some comity with those further South.

One of the key influences driving both the abolition and antislavery sentiments in the North was the reformist impulse that took hold at the beginning of the 19th century and picked up steam in the 1820s and 1830s. This reformist impulse itself was stimulated partly by an optimistic Enlightenment liberalism, but also by religious revivalism. It is almost impossible to understate how important religion was in 19th century America. During and following the revivals of the Second Great Awakening, the United States was an aggressively religious nation, even more so than it is today. In certain expressions, the Protestant revivalism took on what is called a “postmillennial” tenor. Postmillennialism is a form of Christian eschatology holding that in the end times, there will be a thousand year golden age of the church during which many souls would be won to Christ, and the world itself would improve. After this golden age, Christ himself would return in glory to reign on Earth. In its American expression, this got linked with reform movements because many people sincerely believed that by reforming society – improving schools, prisons, liquor laws – they could in some sense bring about the second coming of Christ. For many northern evangelicals, ending slavery was part of this process. Slavery was not just a moral crisis to be faced, it was a struggle towards the creation of the kingdom of heaven on Earth. To many northern evangelicals, slavery increasingly became less an embarrassing feature of southern life to be tolerated, and more of a sin against God, and you cannot compromise with sin. Sin must be extinguished. This type of protestant revivalism was especially influential on some of the more radical white abolitionists in the North.

There’s a key link here as well between Protestant revivalism and 19th century moralism more generally. Protestant moralists raised a number of objections to slavery – the Biblical prohibition on man-stealing being a popular one – but there were concerns as well that slavery led to the moral decay of whites. If slavery continued, so the argument went, then non-slaveholding whites might come to see work itself as something reserved for the “mudsill” of society, to borrow language from James Henry Hammond. For a society concerned with a Protestant work ethic, this is a powerful objection. Northern whites also commonly associated slavery with other forms of moral decay, especially the implications it had for white sexual morality. That slave masters could avail themselves of access to the bodies of enslaved women was not exactly a secret in antebellum America. Protestant moralists recoiled in horror at the mental image created of decadent grandees with veritable “eastern” harems at their disposal. It is also important not to understate the importance of Victorian Romanticism and Sentimentalism in all of this. For 19th century moralists, slavery was just an unkind way to treat other people, and these kinds of arguments were not without their force. There is a reason that Uncle Tom’s Cabin was as popular as it was. Now, you can see someone’s treatment as being unfair or unkind, and still not see them as being fully equal to you. None of this meant that a mainstream antislavery activist or abolitionist necessarily thought in terms of full racial equality.