Resistance to slavery within African societies was as complex and heterogeneous as slavery itself. For enslaved Africans and their descendants taken by force to Europe’s colonies in the Americas, antislavery was an existential struggle. Among European states, Britain was among the first imperial powers to pass laws abolishing its slave trade (in 1807) and slavery in its colonies (in 1833). Antislavery was a transnational phenomenon, but Britain made suppressing the Atlantic slave trade an element of its foreign policy, employing a Royal Navy squadron to search for slave ships, pressing African leaders to sign anti-slave-trade treaties as a condition of trade and coordinating an international network of anti-slave-trade courts. And yet, for many leading British abolitionists, “Africa” was an ideological sandbox—an imagined blank space for speculation and experiment on the development of human societies and the progress of “civilization.”
In the 18th century, early British critics of the transatlantic slave trade argued that “Africa” presented an unparalleled commercial and imperial opportunity. Although the slave trade—and the plantations in the Americas that slave ships supplied with labor—were profitable, some argued that slave-trading regions could, with enough investment, produce goods and commodities that would be many times more lucrative. Moreover, if Britain were the first European power to abolish the slave trade, it might also be among the first to gain a territorial foothold on African soil. Over time, these arguments coalesced into the concept of “legitimate commerce.” A combination of Christian teaching, slave-trade suppression, and commercial incentives would persuade slave-trading polities to give up the practice and instead produce other goods. Legitimate commerce intertwined with a theory of civilization that held that any society that enslaved people was so degenerate in its social development that nearly any reform or intervention was justifiable. By the end of the 19th century, antislavery became a justification for European conquest.
There were at least three broad reform projects launched by British officials and merchants in Africa in the name of antislavery. First, drawing on critiques of the slave trade from the 18th century that emphasized the commercial potential of legitimate commerce, antislavery activists and politicians argued for replacing the slave trade with new kinds of export-oriented commerce. Second, in two colonies, Sierra Leone and Liberia, Britain and the United States experimented with the possibility of using Black people from the African diaspora as settlers and missionaries. In Sierra Leone, more than seventy thousand people, usually known as “Liberated Africans,” were repatriated from slave ships into the small colony. Third, in the mid-19th century, as the transatlantic slave trade declined, Britain and other European powers invested heavily in African plantation agriculture, particularly in cotton and palm oil monocrops.
The African slave population of Portuguese India
