A little-studied aspect of the struggle to abolish slavery in Brazil in the 1880s is the relationship between Joaquim Nabuco, the leading Brazilian abolitionist, and the British and Foreign Anti-Slavery Society in London. The correspondence between Nabuco and Charles Harris Allen, secretary of the Anti-Slavery Society, and other British abolitionists throughout the decade and beyond reveals a partnership consciously sought by Nabuco in order to internationalize the struggle. These letters provide a unique insight into the evolution of Nabuco’s thinking on both slavery and abolition. At the same time, they offer a running commentary on the slow and (at least until 1887-88) uncertain progress of the abolitionist cause in Brazil.