As early as the late seventeenth century, the ethics of slavery were being debated in what would become the United States. As the practice shifted from something more akin to indentured servitude to lifelong enslavement, passed down from one generation to the next, some began to question whether such human bondage should exist at all. Such debate was not born out of nothing, for at the time increasing raids by the Barbary States of North Africa from Italy north to Iceland were dooming many Europeans to a life of enslavement, creating a new found abhorrence which over time spread beyond the confines of European heritage. The first to broadly question slavery, other than those being enslaves obviously, in what is today is the United States, were the Quakers of Pennsylvania, though at first it was only a few, with most households owning a slave or two. However, these ideas began to rapidly spread and be debated amongst intellectuals in Pennsylvania and New England by the early eighteenth century, and by the middle of the century many Quakers not just freeing their slaves, but also actively campaigning against it.
In 1733, the newly created colony of Georgia became the first to outright ban slavery. However, it was not done due to an overt hostility towards the practice itself. Rather, the social reformist founders of the colony viewed it as a place for the poor of Britian to enrich themselves, and therefore slaves would only represent unneeded competition for their labor, creating a situation where the rich could exploit the poor just as they had back in Britain. Ultimately, this experiment failed. Settlers from South Carolina, eager to move south into Georgia, bringing their slaves with them, brought their grievances to the British Parliament, who eventually sided against the social reformers, forcing Georgia to allow slavery in 1750.
Though the first bastion against slavery failed, support against it continued to grow in New England and Pennsylvania, slowly spreading beyond the Quakers. For many of the people in these colonies, the question was more academic compared to the other colonies, many households not having slaves or having only a few slaves, with most slaves working as servants, laborers, and artisans. As slaves in these states were freed, they established small communities, though in most cases they were not viewed as equals, not allowed to own property, and were not allowed to vote, though they were legally protected from kidnapping and re-enslavement. As a result, these communities often became tight knit, with their members doing similar jobs to those they had done while still slaves. By 1771, the colonial assembly of Massachusetts attempted to outlaw the importation or purchase of slaves, but it was vetoed by the colony’s royal governor.
In many ways, the start of the American Revolution turned the sparks of the abolitionist movement into full on flames. For many, it was hard to defend fighting for one’s own freedoms, while actively taking it from others in the worst way possible. Abolitionist societies appeared in most states, and in some even managed to obtain significant political power. Surprisingly, these abolitionist movements found unexpected allies in many of the southern states, the wealthy old money plantation owners. Working together, they convinced every state to pass laws barring the importation of slaves both internationally and from other states. However, while it would be nice to imagine that these rich slave owning asshats were trying to do good, in truth they were just trying to line their own pockets. The breeding of slaves was beginning to become big business, but it was being undercut by imported slaves, hence the want for a ban. By the end of the war, as the political winds shifted and demand for slave labor increased, North Carolina, South Carolina, and Georgia lifted their bans, aiding in the further growth of breeding slaves as a business in Virginia, Maryland, and Delaware, which is exactly as fucking terrible as it sounds.
In the meantime, the abolitionist organizations were pushing for less questionable successes further north. When the Vermont Republic declared its independence in 1777, it also declared slavery to be illegal, forcing anyone who had slaves to leave. In 1780, Pennsylvania passed a law making it so that all children born to slaves would be free, a shitty gradual abolition compromise which resulted in slavery remaining in the state until 1847. Connecticut and Rhode Island followed suit in 1784, with slavery existing within their borders until 1848 and 1842 respectively. Massachusetts, went a different route, with a court case in 1783 declaring slavery to be illegal and all slaves being freed immediately, even though this angered the small group of owners, who felt their property was being stolen from them, which again, is exactly as shitty as it sounds. New Hampshire went an even different route, having very few slaves, rather than passing a law or waiting for a court ruling, they just kind of let slavery fade away, though the last handful of slaves were not freed until 1857. Even the federal government got into the action. When the Northwest Territory was created in 1787, it was declared to be a slave free territory, both to open it up to as many settlers as possible, and also as part of a compromise which allowed the southern states to retain their individual claims on the southeastern frontier. Though not considered a significant issue prior to the American Revolution, by 1790 abolition had definitely become one, an issue which would define American politics for generations to come.