Slavery was never as big in the North as in the South, from the 1790 Census until the 1860 Census
Slavery in the North Compared to the South
As you can tell, this image makes the claims about slavery, that the North (in the terms of the Civil War Era, the “North” referred to non-slave states) having more slaves than the South (again, in Civil War terms, slave holding states) At the time of the Civil War you also had the Border States which were slave holding states that chose not to secede from the Union (either by vote, or by force) they were considered southern states because of the above mentioned terms. Obviously, when you compare them in Civil War Era terminology, this whole meme is self defeating.
I’m a History nerd, I love History, and with all of the talk about the Confederacy lately due to some mentally ill guy shooting people while taking pictures of himself with the Confederate Battle Flag, there has been a lot of misinformation about the flags, the Civil War, and slavery. So as part of my Civil War series, which started with my post about the History of the Confederate Flags I’m going to make my second article about this myth, which I have seen a lot of people claiming on Social Media.
By 1804 all northern states had passed laws at least gradually abolishing slavery, which you can see evidence of with the number of slaves declining in the northern states over each Census Report. Prior to the Civil War and Abolition of Slavery in 1865, one northern state (NJ with 18) and two Territories that supported the North in the War (Nebraska with 15 and Kansas with 2) were the last 35 slaves in the North.
But, this meme also doesn’t specify, even though historical terminology makes the assumption, that it means civil war era. The US Census started in 1790, and Slavery was abolished in between the 1860 and 1870 Census, so you can only compare every ten year census ranging from 1790, until 1860, just before the start of the war.
All Census data used here is taken from the University of Virginia Historical Census Browser  which gets it’s data from the original US Census Reports.
In 1790, there were 13 States and three territories, the Slave Population of each state is listed below along with the total population. New York, New Jersey, Vermont, New Hampshire, Connecticut, Rhode Island, Pennsylvania, were considered the North, and North and South Carolina, Virginia, Kentucky, Maryland, Delaware were considered the South:
The only changes from the 1790 to the 1800 Census was that Kentucky and Vermont are now states, and Tennessee has joined the South.
Between the last two Census reports, Ohio has joined the union as a free northern state.
Between the last two Census Reports Alabama, Louisiana, Mississippi, and Missouri (a territory still) have joined the South, and Illinois and Indiana have joined the North.
From the 1820, until the 1830 Census we have Arkansas and Michigan becoming territories, and Missouri and Maine are now states as part of the 1820 Compromise
From 1830 to 1840 we added Florida, Iowa, and Wisconsin as Territories.
From 1840 until 1850 Minnesota joined as a territory and California joined as a northern state, and Texas joined as a southern state, Florida, Iowa, and Wisconsin are now states.
From 1850 until 1860 Kansas, Nevada, and Nebraska joined as territories, Minnesota became a state, and Oregon joined as a state.