Latest / The Atlantic Slave Trade: Empire Built on Human Suffering — Fexingo History / The Slave Trade's Hidden Numbers: Voyages and Mortality
Transcript
- Lucas: So we've talked a lot about the human stories of the slave trade — the rebellions, the legal battles, the maroon communities. But today I want to zoom out and look at the sheer scale of it. The numbers are staggering, and they carry their own kind of horror. Luna: Numbers? You mean like how many people were taken? Lucas: Exactly. For centuries, historians argued over the total. Some said maybe 10 million, others 20. But in the 1990s, a database project began at Harvard and later at Emory — the Trans-Atlantic Slave Trade Database. It now records over 36,000 individual voyages. And the best estimate is that about 12.5 million Africans were forcibly embarked onto ships between 1500 and 1866. Luna: 12.5 million. That's a city the size of New York City, twice over. Lucas: And it gets worse. Of those 12.5 million, roughly 1.8 million died in the Middle Passage — that's about 15 percent. But that average hides huge variation. Some ships lost fewer than 5 percent. Others lost 30, 40, even 50 percent. The ship 'Jozseph' in 1796 lost half its cargo. Luna: Half. What caused such a high death rate? Lucas: Multiple factors. Disease was the biggest killer — dysentery, smallpox, measles, fevers. But also the conditions: overcrowding, malnutrition, dehydration, and violence. The ships were packed as tightly as possible to maximize profit. There's a famous diagram from 1788 of the Brookes ship, showing how enslaved Africans were arranged on shelves with barely 18 inches of headroom. They were literally chained spoon-fashion. Luna: I've seen that diagram. It's one of those images that sticks with you. Lucas: It became the iconic image for abolitionists. And it actually led to the first British regulation, the Dolben Act of 1788, which limited the number of slaves per ship based on tonnage. But even then, enforcement was spotty. And mortality remained high, especially on longer voyages from places like Mozambique to the Americas. Luna: So the database — does it track where people were taken from and where they went? Lucas: Yes. The majority came from West and Central Africa — Senegambia, the Gold Coast, the Bight of Benin, the Bight of Biafra, and Angola. The largest single origin was probably Angola, with about 4 million people. And about 40 percent went to Brazil, especially to the sugar plantations and gold mines. The Caribbean took another 40 percent, and mainland Spanish America about 15 percent. Only about 5 percent went directly to what is now the United States. Luna: That's surprising. I always thought the US was a major destination. Lucas: It's a common misconception, partly because the US slave population grew so rapidly through natural increase, while in the Caribbean and Brazil the death rates were so high that they needed constant imports. But even though a smaller percentage went to the US, in absolute numbers it's still about 400,000 people — which is a lot. Luna: And the database also shows the names of ships and captains, doesn't it? Lucas: Yes, and that's where the numbers become personal. You can look up a specific voyage — the 'Mary' of Liverpool, the 'Hannah' of Bristol — and see how many people they carried, how many died, where they bought and sold. It's a powerful tool, but also a disturbing one. It forces us to confront the trade not as an abstraction but as a series of deliberate choices made by individuals. Luna: And what about the African side? Did local rulers keep records? Lucas: Not in the same way, unfortunately. But Europeans kept detailed logs, and there are also oral traditions. We know that African polities like Dahomey and Asante were deeply involved in capturing and selling people. They had their own reasons — political power, economic gain, sometimes as punishment for crimes. But the scale and the brutality were driven by European demand. The database shows that the trade expanded dramatically in the 18th century, with more than 6 million people taken in that century alone. Luna: So the 18th century was the peak. Lucas: Absolutely. The busiest decade was the 1780s, with over 900,000 people embarked. That's about 90,000 a year. Every year. Think about that — a ship leaving almost every day, packed with human cargo. And the ships got bigger over time. Early 17th century ships carried maybe 100 people. By the late 18th, some were carrying 500 or more. Luna: And the mortality rate improved over time, didn't it? I think I read that. Lucas: It did, but not because conditions improved out of humanity. It was because captains learned to manage diseases better — like insisting on cleanliness, better food, and shorter voyages. Also, the Dolben Act forced some limits. But even so, the average mortality in the 1790s was still around 10 percent. And for the enslaved, that meant a one-in-ten chance of dying before even reaching the Americas. And those who survived faced a life of brutal labor. Luna: It's hard to wrap my head around those numbers. They're so large. Lucas: That's why some historians argue that we need to focus on the individual stories to truly understand. But the numbers themselves are a kind of story — a story of systematic violence and greed. The database also reveals something else: the trade was not just a few rogue ships. It was a massive, organized business. British ships alone carried over 3 million people. Portuguese and Brazilian ships carried nearly 5 million. The French, Dutch, and Danish all participated. Luna: And the Spanish? Lucas: The Spanish relied on asiento contracts — basically licenses to import slaves into their colonies — and those were often held by other nations, like the Portuguese or the British. So Spanish ships carried fewer, but the total number under Spanish flag was still significant, especially in the 19th century. Luna: So when did the trade officially end? I know Britain banned it in 1807. Lucas: Right, the Slave Trade Act of 1807 made it illegal for British subjects to engage in the trade. But it continued illegally, especially to Brazil and Cuba, for decades. The last recorded slave ship to cross the Atlantic is thought to be the 'Clotilda' in 1860, which brought 110 Africans to Alabama — that's just five years before the end of the US Civil War. So the trade spanned over 350 years. Luna: And the mortality numbers — the total deaths in the Middle Passage alone is about 1.8 million. But that doesn't include deaths during capture or in the barracoons on the coast, does it? Lucas: No, it doesn't. Those deaths are much harder to estimate. Some scholars suggest that for every 100 Africans captured, only about 64 survived to be sold in the Americas. That means the total number of deaths related to the trade — from capture, the march to the coast, the wait in holding pens, and the voyage — could be around 4 to 5 million people. It's a staggering loss of life. Luna: And all that suffering for what? For sugar, coffee, cotton, tobacco. Lucas: Yes. And the profits built empires. The slave trade financed the Industrial Revolution in Britain, fueled the growth of colonial cities like Liverpool and Bristol, and created immense wealth for plantation owners in the Americas. But the cost was paid in human lives. The database is a record of that cost, one voyage at a time. Luna: It's important that we have that record. Even if it's hard to look at. Lucas: Exactly. And the database is still growing. Scholars are adding new voyages from archives in Portugal, Spain, Brazil, and elsewhere. So the numbers will become even more precise. But the essential picture is clear: it was the largest forced migration in human history, and it was built on a foundation of violence and dehumanization. Luna: Well, thank you for walking us through that. It's a lot to take in. Lucas: It is. But it's a necessary part of understanding the full scope of the Atlantic slave trade. And it helps us see the trade not as a distant historical event but as something that was carefully planned, executed, and recorded by the people who profited from it. Luna: Next time, maybe we can talk about the abolitionist movement in more detail — the people who fought to end it. Lucas: That's a great idea. There are so many stories there — from Olaudah Equiano to William Wilberforce, from the Haitian Revolution to the British naval patrols. We'll save that for another episode.