The absolute numbers don't tell the whole story, and illustrate part of the difference between the U.S. and Canada on this.
The Wikipedia article on Canada is horrible on one point: "Black" isn't a single minority group in Canada. We have people from the Caribbean and people from many different regions in Africa and, yes, like U.S. we also have descendants of black slaves (in sometimes surprising places). But while they often share similar skin colourings, that is often the only thing they share in common. Many of the Ghanaians, Nigerians, South Africans, and Caribbeans I know have nothing in common except their skin colour—and their love of partying, at least the ones that I've come into contact with over the last ten years.
So, the 2.5% Canadian "black" population is a substantially more diverse population than the 12.6% U.S. "black" population, which is primarily descended from black slaves. This group may be less diverse, but it's also something that the U.S. must come to grips with as much as Canada must come to grips with its treatment of its Aboriginals (which, to be honest, the U.S. must do, too, but they're not as visible to most Americans).
> So, the 2.5% Canadian "black" population is a substantially more diverse population than the 12.6% U.S. "black" population, which is primarily descended from black slaves.
Maybe half of the US black population is descended from slaves. The rest, which is about 6% (from your numbers) comes from the same places Canada gets its 2.5%.
And then there are all of the different groups under the hispanic label.
> Since the Immigration and Nationality Act of 1965, an estimated total of 0.8 to 0.9 million Africans have immigrated to the United States, accounting for roughly 3.3% of total immigration to the United States during this period.[4] - http://en.wikipedia.org/wiki/African_immigration_to_the_Unit...
> One of the more noted aspects of Black Canadian history is that while the majority of African Americans trace their presence in the United States through the history of slavery, the Black presence in Canada is rooted almost entirely in voluntary immigration.[17] http://en.wikipedia.org/wiki/Black_Canadians
I reiterate the original point: Canada is a substantially more diverse place than the U.S. in terms of places of origin, even though the U.S. has a larger percentage of visible minorities.
Africa isn't the only source of black people. Also, as your source points out, there were basically no controls on African immigration until the 1920s.
BTW, a significant number of fleeing slaves went to Canada....
