Contrary to the popular assumption that centralized political power was necessary to destroy slavery, federal power spent much of its history protecting and enforcing the institution. This privatized costs for a privileged few and socialized and diffused the costs onto others in society. This is a common reality with any state intervention, indeed, it is the point of state intervention.

Why are some resource-rich countries poor while others grow spectacularly wealthy off their natural world?

The relevant question isn’t why some places or people are poor, since that’s the default state of humanity, but why some places and times and peoples have stumbled upon institutions and economic operations that propel them into unfathomable wealth (at least relatively speaking).