Side Effects of Immunities: the African Slave Trade

The resistance of Sub-Saharan Africans to diseases that were plaguing the southern United States contributed to the establishment of African slavery in those regions. Specifically, Africans' resistance to malaria increased the profitability of employing African slave labor, especially that of slaves coming from the most malaria-ridden parts of Africa. In this paper, I first document that African slavery was largely concentrated in the malaria-infested areas of the United States. Moreover, I show that the introduction of a virulent strain of malaria into US colonies greatly increased the share of African slaves, but only in states where malaria could thrive. Finally, by looking at the historical prices of African slaves, I show that enslaved individuals born in the most malaria-ridden African regions commanded higher prices.