Slavery: A Justified Institution As the nineteenth-century emerged, the infamous institution of slavery grew rapidly and produced some surprising controversy and rash justification. Proslavery, Southern whites used social, political, and economical justifications in their arguments defining the institution as a source of positive good, a legal definition, and as an economic stabilizer. The proslavery supporters often used moral and biblical rationalization through a religious foundation in Christianity and supported philosophic ideals in Manifest Destiny to vindicated slavery as a profitable i