I have no idea how many returned from Canada although it is worth noting they did not need to go that far and usually just escaped to the northern US where slavery was not allowed.
As for how they fared economically/socially I have no hard and fast figures except to say generally not all that well. Indeed even today there is a distinct separation between white vs. black prosperity. My most recent copy of The Economist has an article that claims black’s median household income, while much improved over the years, is still only 63% that of whites’.
There was an increasing motivation for them to escape to Canada after 1850.
A new, strengthened Fugitive Slave Law, passed as part of the Compromise of 1850, made it much easier for runaway slaves to be captured in the North and returned to captivity. The new law required the federal government to assist in the return of these slaves, something that had not previously been part of the law. Also, when an alleged runaway was captured, his or her case was determined by special commissioners, who were paid $10 if they found in favor of the slaveowner, and $5 if they found in favor of the (alleged) slave.
In addition to high-profile Boston cases like those of Thomas Sims and Anthony Burns, hundreds of blacks were sent South to slavery after the passage of the 1850 law.
Yes, but there was soon a sizable group of people who refused to abide by that law. Including ‘mobs’ in free states to prevent enforcement of it, and sheriffs & other elected officials who declined or claimed to be unable to enforce the law.
A common complaint of the slave states just before the Civil War was that this law was not being enforced, and that often it was the authorities in free states who were doing the not enforcing.
I’m well aware of that, but the fact that some Northern officials did their best to undermine the new law did not erase the law from existence, and the law’s very existence was sufficient motivation to send increasing numbers of former slaves (and free blacks) north to Canada.
On the one hand, the prominence of cases like the Anthony Burns case hardened the resolve of New Englanders to resist the FSL; indeed, no black was returned to the South by due process from New England after the Burns case. On the other hand, the very public return of people like Sims and Burns to the South, enforced by Federal troops, confirmed in the minds of many Northern blacks that their liberty was in danger from the law.
Showing that there were Northerners who resisted the law does not remove the motivation that some blacks felt to leave the US for Canada, and while there are no exact figures, most estimates place the number that crossed the border in the decade after 1850 at well over 10,000, with an especially large group in the immediate aftermath of of the passage of the FSL.
According to historian Fred Landon, in his article “The Negro Migration to Canada after the Passing of the Fugitive Slave Act” (Journal of Negro History, 5:1, January 1920), 3,000 crossed the border in the few months following the passage of the law. Landon cites numerous accounts from 1850, 1851, and 1852 discussing the increasing numbers attempting to get to Canada.
Also, quite a few blacks ended up in Canada precisely because of the mobs that you mention. Here’s one story from Landon’s article:
Landon and other historians cite numerous other instances of blacks being held in captivity awaiting legal determination of their fate who were then free by abolitionist groups and hurried north across the border.
Well, to be fair, Southern states had been complaining about lack of Northern help since the first fugitive slave law, in 1793. Southern concerns about Northern unwillingness to help return slaves to captivity were, in fact, part of the reason behind the stronger law of 1850.
To the OP:
While Landon’s article focuses mainly on the stories of fight, he does conclude with some observations about the type of life that those who went to Canada were able to make for themselves. Here are a few relevant snippets: