The adjudication of slave ship captures, coercive intervention, and value exchange in comparative Atlantic perspective, ca. 1839–1870

What were the consequences of creating jurisdictions against the transatlantic slave trade in the nineteenth-century Atlantic world? Answering this question requires a comparative focus on the courts of mixed commission that adjudicated naval captures of slave ships, located at Sierra Leone (the foremost site of British abolition) and Brazil (the primary mid-century target). Court jurisdiction conflicted with sovereign jurisdiction regarding the presence of recaptives (“liberated Africans”), the risk of re-enslavement, and unlawful naval captures. To rescue the re-enslaved and compensate the loss of property, regulating anti-slave-trade jurisdiction involved coercive strategies alternating with negotiated value exchanges. Abolition as a legal field emerged from interactions between liberated Africans, British diplomatic and naval agents, and local political elites in Brazil and on the Upper Guinea Coast.