Separate for Profit

I know that we have spoken about this in the past, but I think that I've found a new way at looking at this idea: why is it that there are (at least) two separate histories in the United States? Why is the same history being written separately by the same company?

I know that we spoke about the "black history" vs. "white history" in the United States, but I never thought of the same company publishing books on both, instead of merging them together. How much of this is for the company to make a profit than actually believing that these histories should be told separately? Is it more profitable to separate people and advertise to each group separately?

I know that in marketing, women are seperate from men, the races are split up, and there are even different stores according to where a person lives in the United States, but I guess it never occured to me that profit could go as far as how we separate hisotry.