This article examines three historiographical debates: the comparative history of the United States and South Africa, the relative salience of race and class in labour history and the relationship between industrialisation and the growth of prisons. It looks at these matters through the prism of the rise and decline of convict labour in Birmingham, Alabama, USA and Kimberley, South Africa. Focusing on the development of iron and steel in the 'New South' and diamonds in South Africa, the article demonstrates the ways in which employers made use of convict labour to promote industrialisation, to break attempts at worker unity and, in particular, to mobilise race to divide the workforces. It concludes that there were considerable similarities between the two comparators.