7 key questions about the transatlantic slave trade – answered

A range of cultural justifications were offered for the enslavement and transportation of Africans as slaves, while Europeans quickly developed the maritime skills and practices needed to transport Africans in large numbers across the Atlantic. In the process, African slavery developed not merely as a vital economic force but as a legal concept. Laws governing slave ships and colonial plantation slavery evolved, and all hinged on the concept of the slave as a thing. Africans were bought and sold in the same manner as other items of commerce: they were cargo on board ships and part of the property on plantations. From the first, this created obvious legal and philosophical problems. What happened to slaves when they stepped ashore in the free societies of Europe? Did European rights apply to Africans? What were the boundaries between freedom and enslavement? Such questions, in various forms, taxed slave-holding societies throughout the history of African slavery. They were only finally resolved when the abolitionist concept 'Am I not a man/woman and a brother/sister?' was conceded in law in the course of the 19th century.

Over three centuries, more than 12 million Africans were removed by Atlantic slave ships. More than 11 million survived to landfall in the Americas. Why did the trade last so long? Why did such huge numbers not create viable, thriving populations that increased of their own natural accord?

Firstly, the sexual composition of the captives was important. Where the sexual balance was uneven (with more men or more children), it was difficult for a slave population to grow naturally. Equally, the ill health of Africans landing on the slave ships often militated against normal or healthy patterns of childbearing. The physical and mental traumas of enslavement and travel, and especially the impact of the slave ships, impaired healthy reproduction, not to mention working and living conditions on the plantations. More complex still was the question of links between Africans and Europeans. In societies where slaves greatly outnumbered whites and where Africans dominated the slave force, African customs and habits persisted. Prolonged breast-feeding (common among many African women) tended to suppress the birth rate. Where female slaves had closer social links to European women (who tended to have shorter breast-feeding patterns), slave birth rates tended to be higher.

Once local-born slave women entered child-bearing years, they tended to have more children than African women. This pattern emerged in the Caribbean and in the North American colonies. One result was that the newly formed USA had a growing slave population, and no longer required slaves from Africa. However, where new frontiers and industries opened up – around coffee in Brazil and sugar in Cuba, for instance – large numbers of Africans continued to be imported from Africa. Hence the survival of the slave trade well into the 19th century.

For much of its history, the Atlantic slave system had few critics. Moreover, their voices were usually drowned out by the wealth generated by successful slaving. That began to change, quickly, after the declaration of American independence in 1776. The rise of a new political and religious sensibility – part Enlightenment, part theological – prompted the rise of a widespread abolition sentiment. Though the vested interests of slave trading (merchants, traders and planters) fought a dogged rearguard action, the slaves’ cause became a tide that undermined the slave system. Revolutionary and wartime violence corroded slavery. And so too did the actions of the slaves themselves. Their voices and actions, their defiance, resistance and flight, helped tip the balance. When the west became abolitionist, the most persuasive critics had been the slaves and their allies, who promoted the cause of freedom. And the most persuasive evidence was the horror stories that emerged from the bellies of the slave ships.

Much of our understanding about slavery has been defined by national boundaries (slavery in the US, in Jamaica, in Brazil, etc.) But innovative research on the Atlantic slave trade has exposed slavery as a ubiquitous, global force. For all the obvious boundaries of national interests – in colonial, trading and military affairs – slavery had global consequences. There were extensive trading routes (not unlike the old silk routes) which bound Atlantic slavery to a wider world economy. Goods from Asia found their way onto Atlantic slave ships. Slave-grown produce could, by the late 18th century, be found in far-flung global locations. The profits from slaving enabled western consumers to acquire luxury goods from China – a country that even used silver from the high Andes as its currency. Africans were scattered to all corners of the globe – and so too were the commodities they produced.

For all the obvious boundaries of national interests – in colonial, trading and military affairs – slavery had global consequences

Although the Atlantic slave trade was physically defined by the ocean, its consequences were global, from Africa to the American frontiers – where, for example, great damage was inflicted on native peoples by slave-grown rum, which was exchanged for pelts and furs. More crucially, the importation of African slaves to the Americas helped create a platform for the remarkable material development of the Americas. The slave ships thus contributed to laying the foundations from which the modern world emerged.

The west turned against slavery and the slave trade – slowly – in the 19th century. In 1800, no western state had abolished it. By 1888, it had gone. Or had it? The new imperial determination to end the practice – especially in Africa – uncovered slavery and slave trading everywhere. Western powers now used their military and diplomatic might to stop it (though doing so was often a means of strengthening their own interests). The late-century outcry about atrocities and slavery in the Congo Free State revealed how far the west had turned against slaving. Navies and diplomats united in curbing slave trading in Africa, Arabia and the sea lanes linking them. Long before 1914, abolition had, in the words of Seymour Drescher, become the “gold standard of civilisation”.

And yet slavery re-emerged in the 20th century. The rise of the Soviet Union, with its massive use of forced labour, and especially the Nazis’ vast conquests and enslavement of millions, presented a deeply troubling development in slavery’s history. The practice had been revived, not in distant colonies but in Europe’s heartlands.

After 1945, the drive to put an end to slavery was taken over by agencies of the United Nations. Despite this, it lived on. Scholars reckon that upwards of 40 million people are in slavery today – including trafficked people, child labourers and those entangled in a raft of forms of unfree labour. Slave trafficking thrives because of dire poverty, warfare, corruption and dysfunctional government. The question remains, however: is modern trafficking the same as the Atlantic slave trade?

The Atlantic slave trade is sometimes described as a holocaust. But is this an appropriate or accurate description? No serious student can contest the enormous human damage that spread over such an enormous period of time and space. Nor do serious scholars dispute the levels of suffering and mortality involved on the pestilential slave ships. We need, however, to consider the purpose of the Atlantic slave trade. It aimed to secure enslaved people for the labour markets of the Americas. It was a trade that reduced its African victims to the status of chattel: objects to be bought and sold. At each point of that complex trade – in Africa, on the Atlantic coast and in the slave markets of the Americas – all sides involved hoped for profitable business. And everywhere the story was the same: the weaker and less suitable the enslaved victims, the lower their commercial value.

The human suffering involved – in Africa, on the coast, on the ships and later on the plantations – must not deceive us. Capricious and institutional cruelty was commonplace. Often it was used to secure greater effort from the enslaved. But even in the harshest of shipboard or plantation regimes, commercial profit remained the aim. Though the slave trade involved cruelty and suffering on an extraordinary scale, the purpose was not to damage or destroy the slaves, but to secure the best return from them. So is ‘holocaust’ the best description?

British slave owners shared £20m compensation for the loss of their slaves after 1833. Except for their freedom, the slaves received nothing. US slaves had been promised 40 acres and a mule, but they too got nothing. Though mentioned by some abolitionists, the question of compensation for the slaves – for their loss of liberty, and for their enforced labour from one generation to another – was not seriously considered. In recent years, however, the debate about compensation has resurfaced. The foundations were laid by the post-1945 legal and political settlement of German and Austrian debts. The Nuremberg trials and a string of legal disputes established a link between the concept of crimes against humanity and compensation. This became the basis and inspiration for contemporary campaigns in Africa, the Caribbean, Europe and the Americas for reparations for slavery. The campaign gained strength when adopted by the UN.

Today, the question has become an inescapable feature in political argument on both sides of the Atlantic. It is a debate that, inevitably, draws on historical scholarship. Historians of slavery regularly face questions about reparations: a reminder that, today, slavery still matters. It matters not simply as an important aspect of our historical past, but as a critical ingredient in a complex modern political debate.

James Walvin is professor emeritus of history at the University of York and author of The Slave Trade (Thames & Hudson, 2011) and Freedom: The Overthrow of the Slave Empires (Robinson, 2019).

This article was first published in the November 2019 issue of BBC History Magazine