The Atlantic Slave Trade in the British Empire

The British Atlantic slave trade was, by any measure, one of the largest single commercial enterprises of the eighteenth-century British Empire. The trade, conducted principally by the Royal African Company (1672–1750) and by a substantial number of private British, Bristol, and Liverpool merchants, transported perhaps 3.4 million Africans to the Americas between 1660 and 1807. The Trans-Atlantic Slave Trade Database, established at Emory University in 2008, has documented the embarkation of approximately 12.5 million Africans on European ships in the four centuries of the Atlantic trade; of these, perhaps 10.7 million survived the Middle Passage. Of the survivors, perhaps 3.4 million were carried on British ships. As Hugh Thomas has argued in The Slave Trade: The History of the Atlantic Slave Trade, 1440–1870 (1997), the trade was the largest forced migration in human history before the twentieth century.

The economic importance of the British slave trade has been the subject of a long and serious scholarly debate. Eric Williams, in Capitalism and Slavery (1944), argued that the trade was the principal source of the capital accumulation that financed the British Industrial Revolution. The argument has been challenged by Seymour Drescher, in Econocide (1977), and by David Richardson, in a series of articles in the Journal of Economic History and elsewhere. The consensus, as Joseph Inikori has argued in Africans and the Industrial Revolution in England (2002), is that the trade was a substantial source of metropolitan investment, and that it was a necessary condition for the development of the British slave-based plantation system in the Caribbean, but that its precise contribution to the Industrial Revolution remains difficult to quantify.

The Origins

The earliest substantial British participation in the Atlantic slave trade was conducted through the chartered companies — the Company of Adventurers of London (1588), the Royal Adventurers Trading into Africa (1660), and the Royal African Company (1672). The 1698 decision of the Board of Trade to open the slave trade to all British subjects, ending the Royal African Company’s monopoly, was the structural foundation of the rapid expansion of the Liverpool and Bristol slave trades. Within fifty years, Liverpool had overtaken London and Bristol as the principal British slave-trading port; by 1770, Liverpool was responsible for perhaps 80 per cent of the British slave trade.

The Liverpool slave trade was, in its scale, the largest single component of the British Atlantic slave trade. The slave ships of Liverpool — the Brookes of Liverpool, the Ruby of Liverpool, the Pearl of Liverpool — were among the largest single concentrations of capital in the eighteenth-century British economy. The trade was financed by a complex network of Liverpool, Bristol, and London merchants, of West Indian planters, of shipowners, and of insurance underwriters at Lloyd’s of London. As Marcus Rediker has shown in The Slave Ship: A Human History (2007), the trade was a system of coerced labour that depended on the violence of the shipboard regime: the enslaved were held in chains below decks in conditions of extreme overcrowding, and the mortality rate on the Middle Passage was perhaps 20 per cent.

The Middle Passage

The Middle Passage — the transatlantic voyage from West Africa to the Americas — was the central experience of the British Atlantic slave trade. The voyage lasted, on average, two to three months. The enslaved were held in chains below decks, in spaces that were, in the larger ships, perhaps six feet long, sixteen inches wide, and three feet deep. The mortality rate on the Middle Passage varied, but the average was perhaps 20 per cent. The mortality rate on the West African coast, in the period between embarkation and the Middle Passage, was perhaps another 20 per cent. The trade was, in other words, a system of mass murder on an industrial scale.

The scholarly literature on the Middle Passage has been transformed since the publication of the Trans-Atlantic Slave Trade Database in 2008. The database, which contains information on more than 91,000 individual slaving voyages, has been used by historians to reconstruct the demographic, economic, and social dimensions of the trade with a precision that was not previously possible. As David Eltis has shown in The Rise of African Slavery in the Americas (2000), the British slave trade was, in its scale and brutality, the largest single component of the Atlantic system.

The Campaign Against the Slave Trade

The campaign against the British Atlantic slave trade was the first great humanitarian campaign of the modern world. The campaign was conducted on three fronts: the parliamentary, the popular, and the international. The parliamentary front centred on the introduction of successive abolition bills by Wilberforce: the 1791 bill, defeated by 163 votes to 88; the 1804 bill, blocked in the House of Lords. The popular front centred on the petition campaign, the publication of slave narratives (most influentially Ottobah Cugoano’s Thoughts and Sentiments on the Evil of Slavery of 1787 and Olaudah Equiano’s Interesting Narrative of 1789), and the production of a substantial popular literature of abolition. The international front centred on the 1815 Congress of Vienna, the 1817 Anglo-Portuguese and Anglo-Spanish Treaties, and the 1819 extension of the British right of search.

The 1807 Slave Trade Act, which received the Royal Assent on 25 March 1807, prohibited the British slave trade throughout the British Empire from 1 May 1807. The Act’s preamble was, in its moral language, a remarkable document: “Whereas the African Slave Trade is contrary to the Principles of Justice, Humanity, and sound Policy, and is highly dishonourable to the British Crown, and a proper Subject for the Consideration of Parliament.” The passage is one of the founding documents of the modern British humanitarian tradition.

The West Africa Squadron

The 1808 establishment of the West Africa Squadron, the Royal Navy’s anti-slave-trade patrol, was the enforcement instrument of the 1807 Act. The Squadron was, in its scale, a substantial commitment: by 1850, the Squadron was maintaining some 25 ships and 2,000 men on the West African station. The Squadron’s record was mixed. By 1860, the Squadron had detained some 1,600 slave ships and freed perhaps 150,000 captives. The mortality rate on the Squadron, however, was substantial: perhaps 1,500 British seamen died of disease on the West African station between 1808 and 1860.

The Squadron’s inability to suppress the transatlantic slave trade, despite its substantial commitment, was the result of the limited resources allocated to the task. The Squadron was, at its peak, perhaps 1 per cent of the Royal Navy’s total strength, and the British government was reluctant to commit more. The Squadron was also opposed by the Brazilian slave trade (the last substantial Atlantic slave trade), which continued until 1850, and by the Cuban and Puerto Rican slave trades, which continued into the 1860s. As Hugh Thomas has shown, the British government’s commitment to the abolition of the transatlantic slave trade was, in the end, a necessary but not sufficient condition for the suppression of the trade. The trade continued, in various forms, until the 1860s, when the Brazilian, Cuban, and Puerto Rican slave trades were finally suppressed.

The Aftermath: 1807–1885

The British Atlantic slave trade did not end with the 1807 Act. The trade continued, in various forms, until the 1860s, when the Brazilian slave trade (the last substantial Atlantic slave trade) was finally suppressed. The 1850s and 1860s saw the emergence of the East African slave trade as the major focus of British anti-slavery activity. The 1885 Berlin Conference, which committed the European powers to the suppression of the slave trade in East and Central Africa, was the international moment. The 1890 Brussels Convention was the legal foundation. The 1926 Slavery Convention of the League of Nations was the twentieth-century consolidation.

The British Atlantic slave trade was, in its long-term significance, the founding case of the modern humanitarian legal order. The 1807 Act, the 1815 Final Act of Vienna, the 1926 Convention, the 1948 Universal Declaration of Human Rights, and the subsequent instruments of international human rights law were the legal expressions of the abolition movement. The British Atlantic slave trade was the moral and political precondition of the modern international human-rights regime.

A Primary Source: The 1807 Act

The 1807 Slave Trade Act declared: “the African Slave Trade is contrary to the Principles of Justice, Humanity, and sound Policy, and is highly dishonourable to the British Crown.” The Act, in its preamble, was the first formal use by the British Parliament of the language of human rights in a legislative text. The passage has been the subject of substantial scholarly commentary, and is the most important single document in the history of the modern British humanitarian tradition.

Historiographical Note

The historiography of the British Atlantic slave trade has been transformed since the 1940s. Eric Williams, in Capitalism and Slavery (1944), opened the modern debate with his argument that the trade was the principal source of the capital accumulation that financed the British Industrial Revolution. Seymour Drescher, in Econocide (1977), challenged the Williams thesis. David Brion Davis, in The Problem of Slavery in the Age of Revolution (1975), placed the abolition movement in the broader context of the Atlantic revolutions. The most important recent contributions are Marcus Rediker’s The Slave Ship: A Human History (2007) and the Trans-Atlantic Slave Trade Database, established at Emory University in 2008. The unresolved question is the relative weight of economic and moral causation in the abolition of the trade; the consensus, as James Walvin has argued in The Slave Trade and Its Abolition (2013), is that the answer depends on the specific colony and period under consideration.

In this Section

Other Sections