I'm just wondering, since I haven't been able to find much info on this by poking around on Google: where were free blacks and black slaves in Canada usually from? I know the majority of slaves were from West Africa, but I got a DNA test that said I had a small bit of East African ancestry (I know DNA tests aren't exactly admired by everyone, and I know their limitations, but I did have it verified by Doug McDonald of U of Illinois and he said it was legitimate ancestry and not statistical noise). It's not from my mother's side, who is descended from American colonials in the South. Rather, it's from my paternal grandfather's side, who is Irish, Eastern European, and Canadian. I think it's much more likely to be from the Canadian side, since the East African segment is embedded in British Isles DNA but there were more people of African descent in Canadian history than Irish. I could be wrong, however.
I know that this ancestor could have possibly been Fula, since recent research has shown that they have substantial amounts of East African DNA despite the fact that most of them live in West Africa nowadays. Or, perhaps this ancestor could have been imported directly from East Africa via the Arab slave trade and then was traded off to Europeans at some point. This ancestor could be from Madagascar or Mozambique, a known source of slaves from the European Atlantic slave trade; however, from what I have gathered, people from Mozambique and Madagascar score very low to non-existently in Nilo-Saharan or Afro-Asiatic ancestry, which is what my DNA segment is.
This is something that I doubt will ever be solved. However, I would love to ask folks here who know more about African history and the slave trade history than I do about the demographics of Africans in both Canada and Europe. I'm speaking more about early colonial history as well, most likely the 1700's. I read that there were free Africans in Canada who were part of France's army and navy too around this time. So I suppose my ancestor could have come from that as well. I unfortunately don't know much about the Canadian side of the family except that more recent generations lived in Montreal, but perhaps older generations were from Newfoundland (Just FYI: I'm actually American, not Canadian-just of Canadian descendency).
Here are my distilled questions:
I'd like to know where this ancestor may have come from. If it tested as West African, that'd make more sense. That's common enough among North Americans. But since it isn't, it may make it simultaneously harder and easier to pin down. Thank you!
This is not going to entirely answer your question, since there was substantial migration within the Americas after initial slave importation, but you would probably be interested in the Trans-Atlantic Slave Trade Database (slavevoyages.org), a project which has mapped all currently known voyages in the slave trade. It has great visualization tools that will show you where most Africans imported to Canada came from.
I'm not an Americanist, but in terms of later African migration, the was significant movement of free blacks and slaves during and immediately after the American Revolution. Whitfield, "Black Loyalists and Black Slaves in Maritime Canada" (History Compass) should be a readable introduction to that topic.
For some of your later questions - there were certainly Fula slaves imported to the Americas, and the database should tell you more about Canada specifically. Most slaves from Eastern Africa were imported to South America, not North America, due to the Portuguese connection - but I'm sure there are exceptions. Again, look at the database for more info.
I can't say anything about African soldiers in the French army during the 1700s, or about the origins of black Britons in that period (although West Africa would be my guess, based on the general contours of the slave trade).
There were certainly slaves imported from East Africa to the Arab penninsula and the Indian Ocean world into the early colonial period. Gwynn Campbell has published widely on the Indian Ocean trade; a starting point might be the essays (by Campbell and others) collected in The Economics of the Indian Ocean Slave Trade in the Nineteenth Century (ed. W.G. Clarence-Smith). That's the tail end of the trade; there are other works that cover the earlier period, if you are interested in that.
A final aside - keep in mind that the "Mozambican" slave trade means that slave voyages are leaving from Mozambique; it doesn't necessarily mean that the slaves originally lived in modern-day Mozambique. By the 19th century, slave trading networks spread pretty far inland on the continent, and slaves were traded up and down the East African coast.