Demographic Pressure, Emancipation and Selection into the Great Trek

Households that migrate after a political crisis are not always those most directly harmed by it. We link Voortrekker genealogical records to the 1825 Cape Colony census using machine learning record linkage, obtaining 558 accepted Voortrekker–census links that correspond to 536 unique matched census households. Those households are compared to 9,884 non-Voortrekker households. What distinguished Trekkers from stayers was household composition: Voortrekker households were larger, with more children and more working-age men. Wealth was statistically indistinguishable between migrants and stayers. Within districts, Trekkers held fewer slaves and produced less wheat and wine, the profile of pastoral frontier families pressing against the limits of available land. Using slave compensation records, we find no evidence that households with larger emancipation losses were more likely to trek. In Hirschman’s (1970) framework, exit was exercised not by those most aggrieved but by those for whom exit was cheapest: large, land-hungry households whose demographic circumstances made the interior’s grazing land the obvious destination. These findings offer the first individual-level quantitative evidence for the demographic-pressure interpretation of the Great Trek, and a direct test of the emancipation hypothesis that has been impossible until now.