Is modern racism a product of secularisation and the decline of Christian universalism? The debate has raged for decades, but up to now, the actual racial views of historical atheists and freethinkers have never been subjected to a systematic analysis. Race in a Godless World sets out to correct the oversight. It centres on Britain and the United States in the second half of the nineteenth century, a time when popular atheist movements were emerging and scepticism about the truth of Christianity was becoming widespread. Covering racial and evolutionary science, imperialism, slavery and racial prejudice in theory and practice, it provides a much-needed account of the complex and sometimes contradictory ideas espoused by the transatlantic community of atheists and freethinkers. It also reflects on the social dimension of irreligiousness, exploring how working-class atheists’ experiences of exclusion could make them sympathetic to other marginalised groups.