Antebellum New Orleans sat at the heart of America’s slave and cotton kingdoms. It was also where yellow fever epidemics killed as many as 150,000 people during the nineteenth century. With little understanding of mosquito-borne viruses, a person’s only protection against the scourge was to “get acclimated” by surviving the disease. About half of those who contracted yellow fever died.

Repeated epidemics bolstered New Orleans’s strict racial hierarchy by introducing another hierarchy, what Kathryn Olivarius terms “immunocapital.” As this original analysis shows, white survivors could leverage their immunity as evidence that they had paid their biological dues and could then pursue economic and political advancement. For enslaved Blacks, the story was different. Immunity protected them from yellow fever, but as embodied capital, they saw the social and monetary value of their acclimation accrue to their white owners. Whereas immunity conferred opportunity and privilege on whites, it relegated enslaved people to the most grueling labor.