Endogenous Colonial Borders: Precolonial States and Geography in the Partition of Africa

We revise the conventional wisdom that Africa's international borders were drawn arbitrarily. Europeans knew very little about most of Africa in the mid-1880s, but their self-interested goals of amassing territory prompted intensive examination of on-the-ground conditions as they formed borders. Europeans negotiated with African rulers to secure treaties and to learn about historical state frontiers, which enabled Africans to influence the border-formation process. Major water bodies, which shaped precolonial civilizations and trade, also served as focal points. We find support for these new theoretical implications using two original datasets. Quantitatively, we analyze border-location correlates using grid cells and an original spatial dataset on precolonial states. Qualitatively, we compiled information from treaties and diplomatic histories to code causal process observations for every bilateral border. Historical political frontiers directly affected 62% of all bilateral borders. Water bodies, often major ones, comprised the primary border feature much more frequently than straight lines.