Book of the moment
I'll just add a map to go with that. By far most of the region's African American population lives in the county and historically most within the city proper. Though how that is changing is a story unto itself. Many people beleive that the city population loss is all a story of upper income white households moving to the suburbs, whether inner suburb or exurb. I'm honestly not even sure if that explains most of the migration story for the city these days, it certainly isn't all of it. Here is a map I have... each page is a decade... of the African American population in the county. If you size it to full screen so the image stays static and then flip through the pages you really see the history. I just don't have time to make it into an actual animated graphic to do the same.
and the book released yesterday it looks like: Race and Renaissance: African Americans in Pittsburgh since World War II