The mine wanted labour. The state delivered it.

Rodney’s 1972 book places the transatlantic slave trade and colonial rule in one history of unequal power. Its chapters examine Africa’s development before European dominance, the continent’s contribution to European capitalist development, the expatriation of African surplus, and colonialism as a system for underdeveloping Africa. The proposition is causal: wealth, labour and decisions were redirected through institutions that served outside interests. A description of a railway, a mine or an export as “development” is incomplete until it asks who controlled it and who retained the gain.

The verb matters. Rodney did not claim that African societies had no histories of development until Europe arrived. He challenged the story in which European rule merely encountered a pre-existing absence and supplied progress. His is an interpretation at continental scale; each historical example must still be proved in its own place and period.

The SlaveVoyages project estimates that about 12.52 million captives departed Africa on transatlantic voyages and about 10.7 million disembarked, mainly in the Americas. These are reconstructed totals from surviving voyage records, not a complete roll of names. The difference includes deaths and other voyage outcomes; it must not be presented as an exact count of all deaths, nor as the total human cost of capture and enslavement on land.

Those people were taken into coerced labour systems across the Atlantic. The estimate establishes enormous removal and survival loss on the crossing. By itself, it cannot calculate how much economic development any one African region would otherwise have achieved. Rodney’s wider causal account needs evidence about the subsequent uses of power, trade and labour, as well as this scale of forced displacement.

In a separate study of the British Cape Colony from 1810 to 1910, economic historian Abel Gwaindepi assembled public revenue, spending and debt data. He found that the discovery of diamonds did not simply fill the public treasury and produce broad progress. Competition for mineral rents and a privatized extractive sector helped create what he calls a “minerals-railway complex”; the colony carried heavy debt and deficits as it entered the Union of South Africa in 1910.

This is one settler colony and one account of public finance, not a balance sheet for all of Africa. It nevertheless tests the familiar defence that a mine plus a railway must equal development for the people living there. Infrastructure can move goods and incur public costs while its rewards are captured unevenly. What the track carried is only part of the account. Who paid for it, owned the mineral claim and received the return belongs on the same page.

The slave voyage estimates, the Gold Coast recruitment record and the Cape Colony finance study concern different centuries and institutions. Together they make Rodney’s mechanism legible: removal of people, administrative help for dangerous extractive work, and mineral infrastructure whose public returns could be poor. They are not a single numerical proof of a continent-wide counterfactual. Colonial policy, African action and local outcomes varied, and later development also has causes beyond colonial rule.

A useful audit does not make those differences an excuse to erase the documented transaction. The Gold Coast state could suspend recruitment once the deaths were revealed. That decision shows the assistance was a policy choice, not an unavoidable feature of geology. Rodney’s question remains pointed: when the benefit is reported as progress, where does the report put the people who supplied it?