This article examines the growing involvement of English Catholicism in the antislave trade and anti-slavery campaigns of the nineteenth century. Early in the century, Catholics in England were conspicuously absent from the Wilberforce-inspired crusade to eradicate the slave trade. By the end of the century, Catholics in England played a leading role in that continuing crusade. The article examines several events that led to growing Catholic participation as the century progressed, including the restoration of the hierarchy, the American Civil War, Herbert Vaughan’s missionary endeavours, the death of Charles Gordon in Khartoum, and the celebrated efforts of French Cardinal Charles Lavigerie to end the slave trade in northern Africa. This argument is placed within the greater context of papal encyclicals on the subject of slavery from the nineteenth century and earlier. The article surveys the work and words of Cardinals Wiseman, Manning and Vaughan, as well as the Catholic press, including the Tablet, the Dublin Review, and the Month.