What are "destination cities" in the book, The Devil You Know: A Black Power Manifesto?

At several points in the book, Blow refers to ‘destination cities,’ which are Northern cities to which many Black Americans migrated in the decades following the Civil War. Black Americans migrated there in search of economic opportunity, and in hope of escaping the racial persecution that they suffered in the South. Unfortunately, the racial oppression that they encountered in the North was just as egregious. This fact is one of the reasons why Blow advocates for a reversal of these migrations.