This article examines the historical origins of one of urban Africa’s most visible contemporary problems, using Tanzania as a case study. The middle decades of the twentieth century are identified as a time when a pivotal shift occurred as labour scarcity gave way to over-supply, resulting in the emergence of enduring ‘structural’ unemployment. This was influenced by a combination of phenomena arising from the deepening impact of colonialism: including demographic growth leading to an increasingly youthful population, commoditisation and heightened African expectations influenced by socio-cultural and ideological factors. These were compounded by a shift in late-colonial labour policy towards stabilisation, which had the unintended effect of stymieing job creation. The latter part of the article describes the panicked response of the incoming African regime, faced with what they initially interpreted as a potentially insurrectionary class of urban unemployed. Closing remarks speculate on whether, in the longue durée, one may interpret unemployment in a more positive light as part of an ongoing wider historical transformation.