Well saying black people or white people is an over generalisation so if you go to the sub-saharian African continent

You will find a lot of culture

As for civilization building the continent that is sub-saharan Africa didn't have access

To mammals for domestication they couldn't have hippopotamuses working as cavalry

Also they don't have the waterways that make it easier for people's to build cities and trade

Africa has the world's shortest coastline as well so it's hard to build a seaman traditions

For the USA politically it is very black and white because that his history of race relations within the US

If you are taken from Africa spend 250 years as a slave their won't be much left of the original culture

And people's whom immigrate from Africa when they come to America with in a generation they take on the American identity