Sparse and uneven transport networks fundamentally limit states’ ability to project power and promote development in many African countries. However, not much is known about their historical roots. This project analyzes the colonial causes and consequences of transportation networks in colonial Africa between 1900 and 1966. I argue that colonial transport networks where mostly built to connect potential centers of production with ports rather than to facilitate exchange between colonies’ inhabitants or defend territory against challengers. Lowering transport costs to ports, (rail)roads unleashed local cash crop and mining revolutions, increasing exports and filling the states’ coffers with taxes on the same. Empirically, I collect data from British administrative reports to reconstruct the evolution of transportation networks in 8 colonies until 1940 and draw on a continental cross-section of roads observed in 1966. Using tools from network analysis, I assess local mineral and agricultural resources as one driver of networks’ geographical development. The results shed light on the extractive origins of colonial state building.