btw...I am very familiar with slavery. I am a 7th generation Mississippian and was once married to a Brasilian and have lived throughout the Carib Basin and South America and West Africa.
The reasons slaves fared better in North America was not simply economic or climatologiocal but cultural as well.
There are reams of works out there detailing that mistreatment of slaves was frowned upon here for the most part.
The great irony is that slavery in Brasil where it was harsher inadvertantly resulted in a more mixed race society ultimately even under harsher conditions....
Yes...there were some slaves for a time in Canada.
The brakes on slavery began with the UK if I'm not mistaken and involved recompense...an idea that never got very far here.
Too many zealots on both sides....not unlike today actually but of course I feel as right now as they did then..lol
Actually, the first governmental units to reject slavery were the legislatures of the states of Pennsylvania and Massachusetts in 1780 when they passed legislation to end slavery in their states. Granted, they were "gradual emancipation" measures, but they were a very radical step at that time in keeping with the ideas of liberty that the war was being fought over. This was at the height of the Revolutionary War when the British were still the driving force in the Atlantic slave trade and before the British conscience kicked in.