Recent studies have highlighted the importance of Africa's history of slave exporting to its current economic development. In this paper I show that differences in investment in education may be one of the channels through which that history has affected current development. I combine data on literacy rates of administrative districts from the colonial censuses of Nigeria and Ghana from the 1950's with data on slave exports of different ethnic groups. I find a negative and signicant relationship between slave export intensity before the colonial era and literacy rates during the colonial era. I also use contemporary data on literacy rates from the 2010 Nigerian Literacy Survey and find that this negative relationship is still present and significant. Thus, I show that the slave trades affected development through channels other than inter-ethnic group confliict or formal nation-state level institutions.