The non-human species spread early in pre-history, so they're pretty evenly distributed. There are plenty of cultural differences between different regions, species really doesn't play all that big of a role - of course, the very existence of multiple intelligent species affected how culture developed, but it's not like all the members of one species shunned all the members of another. I'm still working out some of the history, not quite up to the communism/capitalism debate yet, but I do plan to draw lots and lots of inspiration from real life history and culture.