Abstract
In the 1920s, Lewis Mumford correctly predicted that the rest of the century would be dominated by a “Fourth Migration” from the central cities to their suburbs. In this article I argue that we are now at the beginning of a fifth migration that will reurbanize precisely those inner-city districts that were previously depopulated. I identify four sources for this trend: downtown reurbanism; immigrant reurbanism; Black reurbanism; and White middle-class reurbanism, and point out the challenges involved in planning the fifth migration.