Why do blacks live in urban areas?

On a very abstract level it seems to make sense if for example whites are more self sufficient than blacks. So non self sufficient blacks would live in urban areas because urban areas are where society is, so on an abstract level it would make sense that someone who relies on society to survive would live would live in an urban area. But in practice I don't see how it works, because suburban housing is cheaper, so it would make sense to me if poor blacks live in the suburbs, and then commute to their work wherever that might be. So why do we instead see a large density of poor blacks living in crowded urban areas where housing is overpriced?