The Slave Trade and the Foundations of U.S. International Legal Thought, 1808–1870

Abstract

The international policing of the Atlantic slave trade transformed U.S. ideas and attitudes about international law between the U.S. ban on this trade in 1808 and the trade’s closing in 1870. This dissertation is the only major study in over eighty years of the U.S. debates over whether to join Britain’s international efforts to suppress the slave trade and the first to integrate the diplomatic correspondence over treaty negotiations for a peacetime right of search to capture foreign-flagged slave ships with legal cases, pamphlets and treatises on international law, congressional records, and abolitionist newspapers. This broader study reframes a narrative of consistent U.S. resistance to the international legal strategy as a story of change from support to resistance because of American slavery and the way it engendered new American interests in sovereignty at sea. Americans were initially divided over international suppression, with advocates of colonization in Liberia and proponents of judicial power over maritime commerce in support. But international suppression became linked to the gradual abolition of slavery in the British West Indies, which broke down the distinction between slave trade abolition and slavery abolition much earlier in the international context than the national one. However, because American lawyers and diplomats could not resist the international regime by defending a trade that remained criminal and taboo in the United States, they instead argued about the rules and scope of international law vis-à-vis American law. The unintended result was a new boundary between the national and international legal orders, visible in decreased U.S. openness to legal pluralism and customary international law, a narrower view of the federal treaty-making power, and a new confidence in American solutions to global problems like the Atlantic slave trade.