Numbers remain unwelcome facets of African history. Foreigners collected most of them until independence, and after independence the published numbers tend to reflect Africa’s lack in terms of economic and social development. Of course, these numbers, most of which have been extrapolated from trade and population statistics, reflect the preoccupations of those who collected them. Thus, many African historians rightly ignore the numbers to tell other types of African history.

Nonetheless, African historical sources contain quantifiable information. Economic historians tend to use this information to model changes in Africa’s history over time, notably its long-term trade engagements with the rest of the world. Thus, economic historians mine the historical records maintained by coastal traders and companies to understand how exports, for example, shaped the histories of Africa and Europe.

Another major field of study drawing on numbers is the Atlantic slave trade. The publication of the first edition of Slave Voyages in 1999, a searchable database on CD-ROM, greatly enhanced the possibilities in this field. Scholars used the database to find information about individual ships as well as quantitative summaries of the number of slaves transported. Even social and cultural historians have used the database to investigate the formation of specific African diasporas in the Americas.

I am interested in finding other ways to repurpose the tools of quantification in African history. One way I think this is possible is the use of commodity data recorded during the colonial period. The most complete records are for colony imports and exports, and economic historians continue to use this data to measure, for instance, the long-term effects of extraction on African nations. My interest in this area is connecting commodity numbers to related histories of internal trade and production.

Moreover, I am interested in the historical records maintained by customs agents along African borders. These records contain quantifiable information related to social and cultural histories that extend beyond the borders of individual colonies or nations. In this sense, commodity numbers can lead to new types of African histories.