[akira2501]

> the migration of formerly-enslaved Black Americans out of the rural south and into cities

My understanding is this is where it started but the mass migration of everyone off of the farm really started to happen when gasoline engines became standard equipment and replaced beasts of burden.

> and lot sizes continue to slow urban, transit-oriented redevelopment.

I'm not convinced this is the entirety of the problem, fortunately US policy is not a monolith, and several cities are experimenting with different configurations. It will be interesting to see if "developers" start opting for the multiplex configurations that are now being allowed in traditional single family zones.