Each of the decades of the nation’s history prior to 1810-1820 saw at least one state abolish slavery. None would do so again until the 1860s. The importation of slaves ceased, legally, at the start of 1808. By then only South Carolina still did so, but smugglers took up some of the slack by dodging Navy patrols or running slaves across the border from Florida and Texas. The last year of the decade saw the Missouri Compromise, which continued earlier precedents for dividing the nation between slave and free territory. It accounted for all the land in the nation, until the nation took some more from Mexico, and so formed a kind of touchstone for those trying to settle sectional disputes in the generation to follow.
One can stretch the idea of turning points too far. Large subjects in history come down mostly to processes rather than single points in time, but certainly the second decade of the nineteenth century marked a kind of transition from a national order that imagined slavery’s inevitable and happy decline and to one based on a perpetual balance of power between sections divided by the legal status of slavery.
In 1820, the nation stood 15.15% enslaved, down from 16.45% in 1810. Of those 1,535,199 slaves, only 19,100 (1.24%) lived in the North., down from 2.13% in 1810. As before, New York and New Jersey account for vast majority (92.34%) of the nation’s slaves between themselves. Nowhere else had more than a thousand, though Illinois comes very close at 917 (4.80% of the Northern total and 1.66% of its population). By national standards, no northern locale is significantly enslaved. By the standards just of Northern demography, 0.91% enslaved counts as significant. New Jersey and Illinois hold that distinction in 1820, with late emancipation and a combination of geography and a free state constitution that allowed “apprentices” for life doing much to explain their divergence.
Down South lived 98.76% of America’s slaves. The upper band of the national norm for slavery in 1820 stands at 30.57%. The Southern regional demographics exceed that. As a whole, 33.84% of the section’s population lived in bondage. Alabama (32.91%), Georgia (43.89%), Louisiana (45.02%), Mississippi (43.49%), North Carolina (32.09%), South Carolina (51.35%), and Virginia (39.91) exceed the norm on their own. By Southern standards, anything above 45.89% counts as unusually enslaved. South Carolina maintains its place of distinction and by 1820 has recovered its colonial-era status as a majority-slave jurisdiction, further South demographically than the South itself.
The minimum level of slavery necessary to count as Southern in 1820 stands at 21.79% of the population. Just as in past censuses, the South has some under performers: Arkansas (11.33%), Delaware (6.20%), the District of Columbia (19.37%), Missouri (15.35%), and Tennessee (18.95%). The least of these, however, still exceeds New Jersey’s 2.72% by a healthy margin. As this pattern persists over all four censuses, and knowing how things work out in the 1860s, I feel confident in calling it a meaningful trend.
While the legal status of slavery might evenly divide the nation in two, the demographics argue for something more like a two and a half section model. The North stands wildly out of pace with the rest of the nation, far more free than the South as a whole and even more free at its most enslaved than the South’s least enslaved place. The South forms the second section, but its upper reaches are out of pace with the rest just as they don’t fall in step with the North. They come in too Southern to qualify for the normal in the North, but too Northern to qualify for normal in the South.
I call the border states/upper south bloc half a section because as a practical matter they tended to vote Southern in most cases, even if a few peeled away to vote Northern as part of the general pro-compromise Lower North/Upper South demographic. But then that demographic did not form its own coherent bloc that happily lined up as one for each compromise. Rather, architects of compromise like Henry Clay and Stephen Douglas found the few extra votes they needed within the group to join to the general unanimity of the sections otherwise. The cut and thrust of Southern loyalty (which in practical terms meant loyalty to slavery) politics created ample room for Upper South politicians to court the ultras to show up less dedicated opponents or shore up their own flagging fortunes. Likewise when their local interests came into play, as they did with the Fugitive Slave Act, Upper South politicians could go more Southern than the Deep South, which for geographic reasons had far fewer runaways to reclaim to begin with.