Slavery's economics: from the Civil War to Congo's cobalt mines

The Short Version

Across three very different conversations, the same pattern keeps showing up: forced labor lasts as long as it pays, and it is hidden from the people who profit from it. Civil War historian Gary Gallagher argues that slavery caused the American Civil War because it was thriving, not dying: in 1860 enslaved people were worth more on paper than all American industry and railroads combined [1]. Siddharth Kara traces a line from the Atlantic slave trade, which he says gave birth to modern finance, banking and insurance, to the hand-dug cobalt mines of Congo, where he estimates roughly 37 percent of diggers work in conditions of absolute slavery to feed phones, electric cars and now AI data centers [2]. Darryl Cooper adds the structural view: the Atlantic trade was a game-theory trap that no single ruler could leave, and industrial consolidation, from Rome's slave estates to factory farms, keeps pushing people into worse positions [3]. Following the money does not explain everything, and the sources disagree about how much credit belongs to conscience rather than power, but it explains why exploitation is so hard to end and why it keeps coming back in new forms.

Table of contents

What They Said

Gary Gallagher: slavery was the richest thing in America, and that is why there was a war

Gallagher, speaking with Lex Fridman, is blunt about causation. By the winter of 1860–61, he says, every condition for war was tied to slavery [1]. His one-line summary: "In terms of causation, if you take slavery out of the picture, there is no civil war, period." [1]

The heart of his argument is economic. He rejects an older school of historians who called the war "needless because slavery was supposedly withering away. That's absolutely wrong," he says. "It was not on its way out. It was thriving. [1] He points out that slavery was not frozen in a cotton-field past: It was making the transition from cash crop agriculture to industrial applications and other applications," beyond just cotton, rice and sugar [1]. Lincoln himself, Gallagher notes, once guessed it might have lasted another 50 years [1].

Then comes his favorite piece of evidence. "The 1860 census is our friend," he says [1]. It shows that the people who controlled the most wealth in the United States were slaveholders, and that "their property in slaves alone, not their their other holdings, not their land holdings, just property and slaves, were valued at about $3 billion. The value of all industries, all railroads, all of that put together, fewer than $2.5 billion." [1] His conclusion: "So it was the most valuable industry in the United States." [1]

That money explains the politics. The flashpoint was not abolition, which Gallagher says was the cause of a small and much-despised minority; the Liberty Party peaked at about two and a half percent of the vote in 1844, and he guesses true abolitionists were about 3 percent of white Americans [1]. The flashpoint was expansion. The 1860 Republican platform promised to leave slavery alone where it existed but block its spread into federal territories. White Southerners read that as a path to permanent minority status and eventual federal interference with the most valuable property they owned [1]. Gallagher also argues that every white Southerner, not just slaveholders, had a stake in slavery as a tool of social control [1].

He applies the same follow the interest logic to the Confederacy's favorite slogan. On "state rights," he says only one right really mattered: using state power to protect slavery. Northern states used exactly the same logic in reverse with personal liberty laws, trying "to interpose their state power in between a federal government that would use its power" to send escaped people back into slavery [1]. "It's whoever's unhappy with federal government, the concept of state rights is available, and both sides used it." [1] And he points to the irony that the Confederacy passed the first national conscription law in American history, and was, in his words, "the most intrusive central government in American history by far until deep into the 20th century." [1]

Slave labor was also the Confederacy's war engine. Gallagher explains that enslaved labor kept the Southern economy running and let the Confederacy mobilize "between 85 and 90 percent of all their white military age males. It's an astonishing mobilization. It's only possible because enslaved labor keeps the economy going." [1] That is why the Emancipation Proclamation was, in part, a military strategy: take the labor away and you strike at the South's ability to fight [1]. Lincoln wrote it dryly on purpose, grounding it entirely in his war powers; one historian said it had "all the soaring language of a bill of lading." [1] Gallagher's point is that Lincoln "doesn't have the power to strike at slavery in the absence of a war." [1]

Finally, Gallagher argues the war ended slavery far sooner than anything else would have. Without it, he thinks, the United States "would have had the ignominious distinction of being the last place to get rid of slavery," after Brazil and Spanish Cuba [1]. Fridman adds a piece of global context: only about 4 percent of Africans carried across the Atlantic went to what became the United States, while Brazil and the Caribbean took over 90 percent, with 4.9 million to Brazil and 4 million to the Caribbean [1].

It is worth keeping Gallagher's own caveat in view. Cause and motivation are different things. Slavery caused the war, but most white Union soldiers fought for the Union, not for emancipation [1]. The money explains why the South left; it does not by itself explain why a Vermont farmer picked up a musket [1].

Siddharth Kara: the same machine, with new metals

Kara, author of Cobalt Red and The Zorg, makes the pattern argument most explicitly, and he makes it in both directions: from the past to the present, and from the present back to the past.

The Atlantic trade as the birth of the global economy. Kara says Americans learn about plantations and cotton, "But we don't learn the details of how they got here and how the first global economy was born around the Atlantic slave trade, how modern finance, banking, and insurance was born through the slave trade." [2] He calls the Zorg the most consequential of more than 40,000 slave voyages, which carried 12.5 to 13 million Africans [2].

He traces the money back to its source. The trade grew out of Portuguese sailing innovations like the lateen rig and Europe's discovery of sugar during the Crusades; the Pope divided the world between Spain and Portugal in 1494, and King Charles signed a 1518 contract to bring Africans to Spanish colonies [2]. Sugar, Kara says, was "the fossil fuel of the day." [2] On the eve of the American Revolution, Jamaica's sugar exports were worth five times all exports from the 13 colonies combined [2]. That is the same kind of comparison Gallagher makes with the 1860 census: the forced-labor sector dwarfing the "respectable" economy around it.

The conditions were designed around cost. Captives were held for months in places like the dungeon at Cape Coast Castle in Ghana, where up to a thousand people could be kept and where, a guide told Kara, a smooth patch of floor is the sediment of centuries of human waste [2]. On ships they had about 16 inches of space each and were stowed, in slave-ship captain turned abolitionist John Newton's phrase, "like books on a shelf." [2]

Murder as an insurance claim. The Zorg story is where the money logic becomes grotesque. After a British privateer captured the Dutch ship in 1780, it was bought on credit tied to Liverpool merchant William Gregson and overloaded with 440 Africans [2]. Under the incompetent Robert Stubbs, navigation errors carried the ship three days past Jamaica and the crew ran short of water. Over three days they threw 130 to 140 Africans overboard, including a baby [2]. Gregson then filed an insurance claim for the lost "cargo. The case reached Chief Justice Lord Mansfield, who said the case of the slaves is the same as if horses had been thrown overboard." [2] The trade had been fully financialized: human beings were an insured asset, and killing them was an accounting question.

What broke it open was not the money but a moral interruption. An anonymous letter asked why no one was talking about murder; Olaudah Equiano brought it to Granville Sharp, who pushed for a retrial and had it transcribed. On the stand, Stubbs admitted it had rained while the captives were being thrown overboard, which undercut the claim that the killings were necessary [2]. Kara says he has identified the letter's author as abolitionist James Ramsey [2]. In 1787, twelve men met in a printing shop and committed their lives to abolition, using viral images, testimony, investigative journalism and consumer boycotts [2]. Kara stresses how much money stood against them: "Most members of parliament had investments in the slave trade and profited from the sugar economy. But they succeeded." [2]

Even abolition followed the money. Britain's 1833 abolition law passed only after the government paid slave owners £20 million, about 40 percent of the national budget at the time. It borrowed the money, and British taxpayers were repaying that loan until 2015 [2]. The enslaved, not the owners, bore the cost of transition: they had to serve five years of unpaid "apprenticeship" before freedom arrived on August 1, 1838 [2]. And the East India Company's territories were excluded from the law, which Kara links to the shipment of Indian laborers to the former sugar colonies [2]. In other words, when one form of forced labor was closed, the money found another.

On reparations, including Jamaica's recent request, Kara lays out the case that Jamaica made: England took millions of Africans, enslaved them, and "made yourself from this muddy medieval back-asswoods island to an economic superpower with centuries of wealth on the back of largely sugar slavery." [2] He offers an analogy: if your father worked 30 years at a plant and was never paid, "He should be paid for that work. The company made their money off his labor." [2] But he also acknowledges hard questions about distribution and corruption, and says he holds no firm opinion [2].

Congo: the pattern today. Kara's present-day research is where the pattern stops being history. Rogan puts the paradox plainly: at the base of all our greatest technology, "you have slave labor or pulling minerals out of the ground." [2] Kara agrees: "you have slave labor, you have child labor, you have militia run mines." [2]

His numbers come from a report called Blood Batteries, published through the University of Nottingham [2]:

• On any given day, at least 300,000 people dig for cobalt by hand.
• About 37 percent work in conditions Kara calls absolute slavery.
• Nearly 10 percent, roughly 30,000, are children.
• Time-lapse satellite imagery shows 40 to 60 percent of forest, shrub and grassland in the copper-cobalt region had been replaced by mining territory by 2022.
• Water in Kolwezi carried heavy metals, including lead, cobalt, copper, uranium and chromium, at 10 to 950 times World Health Organization safe limits [2].

His own pH tests near Kolwezi read 6.7 in the Lualaba River, while local wells and streams tested in the fours and threes [2]. He explains why: ore containing cobalt, copper, nickel, silver and some uranium is separated with "heavy industrial acids toxic industrial liquids," and "they pump that stuff right into the ground." [2]

Crucially, he says this output does not stay in some separate black market. It flows into the formal supply chain through militias and traders [2]. "The bottom of the chain is tainted in child labor, slavery, violence, environmental destruction and contamination. And the new fever is the AI data centers." [2] Circuit boards, servers, heat sinks and energy storage all need cobalt, copper, tin and tantalum [2]. Switching chemistries doesn't escape the problem: one of the world's largest lithium deposits, near Manono, began shipping under a Chinese company, and Kara says conditions there are just as horrific [2].

The resource curse, and a long history of extraction. Kara places Congo's cobalt in a longer chain of extraction from the same ground. The southeastern corner, from Lubumbashi to Kolwezi, was mined for copper going back to colonial times, and "something like a quarter of the bullets used in World War I were copper from that part of the Congo." [2] The uranium in the bombs dropped on Hiroshima and Nagasaki came from the Shinkolobwe mine in the same region [2]. He also relays, while stating plainly that he cannot verify it, claims that Chinese mining trucks have carried uranium to China alongside other ores for 15 years [2].

When Rogan asks why a place with some of the most valuable resources on earth is one of the poorest, Kara answers: "it's the resource curse you know when we find treasure somewhere it attracts the pirates to come in and loot the place." [2] War, colonization and corruption mean "you can get people to work for basically nothing," because there is "virtually nil alternative way to survive." [2] That is the economic engine of forced labor in one sentence: extreme value plus no alternatives.

Abolished on paper. Kara rejects the comfortable idea that slavery is behind us. "We abolish slavery right here. But there's more slaves on earth now than there were. during the time of the Atlantic slave trade." [2] "So we abolish slavery on paper," he says, but "the institution of oppressing, subjugating, and extracting the labor of someone persists and has evolved into the modern era." [2] Rogan extends the point to home, asking how many undocumented underage workers are working in the United States [2].

Hypocrisy, again following the money. Some cobalt deposits exist in North America, Kara notes, but people here won't accept the environmental damage of mining them; meanwhile, Chinese state-run companies in Congo operate with no deforestation offsets or containment, and Western tech and EV firms buy from them anyway [2]. "We can't save our piece of the planet by destroying their piece of the planet," he says [2]. And even if recycling someday ended the need for new cobalt, he insists companies "can't just walk away." If they pillage the place for three decades and then leave, "we're right back to colonial slave trade times, where Europeans did go around the world, scouring labor resources, ransacking, pillaging, and then carrying on their merry way." [2]

Darryl Cooper: systems, incentives and consolidation

Cooper's conversation with Rogan (only his summary is available here, so there are no direct transcript quotes) comes at the question from the angle of structures rather than villains [3].

The Atlantic trade as a game-theory trap. Discussing the great-man-versus-trends-and-forces debate, Cooper argues that the Atlantic slave trade became a kind of game-theory trap: any ruler who refused to take part would be overpowered by one who did [3]. It ended only when the British Empire became dominant enough to enforce abolition at sea [3]. On this view, money and power did not just motivate the trade; they locked everyone into it, and only a bigger concentration of power could break the lock.

Industrial consolidation and displaced people. When Rogan predicts that future generations will view factory farming the way we view slaveholders, Cooper compares industrial agriculture to Rome after its conquests [3]. Estates worked by slaves pushed small farmers off the land and into the city, creating the mob that helped end the Republic. Stalin, he notes, forced the same consolidation through violence [3]. The pattern is that when production scales up on cheap or coerced labor, the independent producer is squeezed out, with political consequences far beyond the farm.

Cheap labor as an American constant. Cooper also notes that exploiting immigrant labor is an old American story, citing Irish dock workers in the 1850s who lived about 14 years after arriving [3]. Rogan argues that current immigration partly serves to supply cheap labor, which he calls anti-American, and says everyone working here should be paid like an American [3]. Cooper calls the early labor movement "America's best story in my opinion," describing the Battle of Blair Mountain, where 10,000 to 11,000 armed West Virginia coal miners marched against mine-company forces until the US Army arrived, and a Colorado massacre in which the National Guard fired machine guns into a striking miners' camp, killing about 22 women and children [3]. Owners treated strikes as sabotage and hired Pinkertons and ex-convicts to spy on, kidnap and beat organizers [3]. He adds that for much of its history America was built for strivers rather than ordinary workers, who were largely forgotten until they pushed back [3].

A caution about whose story we hear. Cooper also reminds listeners that historical sources come overwhelmingly from a small literate, adult, male, upper-class slice of society [3]. That matters for any history of forced labor: the people doing the work are the people least likely to have left records, which is exactly why Kara's ground-level research and the Zorg trial transcript are so valuable [2][3].

Where They Agree, and Where They Don't

They agree that forced labor was an economic core, not a side issue. Gallagher's census figures make slavery the most valuable asset class in the United States [1]. Kara makes Atlantic slavery the foundation of the first global economy and of modern finance and insurance, with Jamaica's sugar outselling all 13 colonies fivefold [2]. Cooper treats the trade as a system so profitable that no ruler could afford to leave it [3]. All three reject the idea that slavery was a dying relic that would have faded on its own. Gallagher says so directly [1]; Kara says it has not even ended, only "evolved into the modern era" [2].

They agree that exploitation shifts shape rather than disappearing. Gallagher describes slavery moving from cash crops into industrial applications in 1860 [1]. Kara shows Britain replacing enslaved labor with unpaid "apprenticeship" and then with shipped Indian laborers, and Congo moving from copper for bullets to uranium for bombs to cobalt for phones and AI [2]. Cooper shows the same squeeze in Rome's estates, Stalin's collectivization, factory farming and 19th-century immigrant labor [3].

They differ on what ends it: conscience, war or power. This is the real disagreement, and it matters for what readers should do.

• Kara emphasizes conscience. He traces abolition to "these little acts of conscience," an anonymous letter and a handful of men in a printing shop, and he repeatedly credits faith as the abolitionists' driving force [2]. He believes a similar movement is forming now around Congo [2].
• Cooper emphasizes power. His game-theory account says the trade ended only when Britain was strong enough to enforce abolition at sea [3]. Moral arguments matter, but without enforcement the trap holds.
• Gallagher sits between them, with war as the mechanism. In the United States, the abolitionists were a small, despised minority [1]. What actually ended slavery was a war, and emancipation followed the advance of the U.S. Army [1]. Kara agrees on this point for America: "It required a civil war, but it was achieved." [2] Gallagher also insists individuals mattered; he argues Lee's success at the Seven Days kept the war going long enough to make emancipation a Union aim, and that a quick McClellan victory in 1862 might have ended the war with slavery intact [1].

These views are less opposed than they look. Kara's own story shows conscience needing power to win: Britain's abolitionists still had to buy off owners with £20 million, and Frederick Douglass went to Thomas Clarkson to learn how the British movement had succeeded so he could apply it in America [2]. Cooper's view explains why the fight took so long; Kara's explains why it started at all; Gallagher's explains how, in one country, it was finally forced to a close.

They differ on how fixable the present is. Kara is strikingly practical: he says fixing mine conditions is simpler than designing a smartphone, requiring protective equipment and containment of toxic runoff [2]. He even notes early signs that a U.S. mining company run by former military personnel, operating under a Trump administration minerals arrangement, is improving artisanal standards [2]. Cooper's game-theory lens implies more pessimism: if one buyer walks away and another steps in, the trap persists, which is roughly what Kara describes when Western firms keep buying from Chinese operators without containment [2][3].

Why It Works

The sources give several mechanisms for why following the money explains exploitation.

Value creates the stakes. When human labor is the most valuable asset in an economy, its owners will fight for it. Gallagher's $3 billion versus under $2.5 billion comparison explains why expansion into the territories was worth secession to white Southerners [1].

No alternatives make coercion cheap. Kara's resource-curse account is precise: treasure attracts looters, and in a war-torn or corrupt place "you can get people to work for basically nothing" because there is no other way to survive [2]. The same dynamic sits under Cooper's Irish dock workers and coal miners [3].

Distance hides the cost. Kara's cobalt passes through militias and traders into the formal supply chain, so by the time it reaches a phone or a data center, the buyer never sees the pit [2]. The Zorg's owners saw their victims only as an insurance line item, and Mansfield ruled on them as if they were horses [2]. Rogan's phrase for the result is that the base of our greatest technology is slave labor [2].

Competition locks the system in. Cooper's game-theory trap explains why even rulers who might have preferred otherwise kept trading: refusing meant being overpowered [3]. Kara's description of Western companies buying from operators with no environmental controls shows a modern version of the same pressure [2].

Coerced labor multiplies power. Gallagher shows that enslaved labor let the Confederacy put 85 to 90 percent of its white military-age men in uniform [1]. Forced labor is not only profit; it is capacity, which is why removing it, as the Emancipation Proclamation aimed to, was a military weapon [1].

The money finds a new channel when one closes. Britain's apprenticeship system, the exclusion of the East India Company's territories and the shipment of Indian laborers to the sugar colonies show that abolition on paper can redirect exploitation rather than end it [2]. Kara's abolished on paper line is the summary of that mechanism [2].

Where It Applies, and Where It Doesn't

It applies strongly to explaining why systems of forced labor persist, why their defenders fight so hard, and where to look for them today. If you want to find exploitation, look for high-value goods, weak states and long supply chains; that is where Kara's Congo, the Atlantic sugar trade and the antebellum cotton economy all sit [1][2].

It applies less well to individual motivation. Gallagher is careful here: slavery caused the war, but most Northern soldiers fought for the Union, an idea about self-government and the legacy of the Revolution, not for money or emancipation [1]. He also stresses that white Southerners who owned no slaves still had a stake in slavery as social control, which is about status and fear as much as profit [1]. Money explains the structure; it does not explain every person inside it.

It underrates conscience if taken alone. A purely economic reading cannot explain why twelve men in a printing shop, facing a parliament full of slave-trade investors, gave their lives to abolition, or why Thomas Clarkson rode 35,000 miles gathering evidence [2]. Kara's whole second half is an argument that moral interruption changes history [2].

It underrates contingency. Gallagher argues Union victory was not inevitable; a Confederate "tie" would have been a win, and slavery might have survived for decades [1]. Economic forces set the stage, but battles like the Seven Days and the capture of Atlanta decided the outcome [1].

Some claims carry uncertainty. Kara is explicit that he cannot verify reports of uranium shipments to China [2]. His prevalence figures are estimates from a single research report [2]. Cooper, by his own account, is a storyteller rather than a credentialed historian and warns that sources are narrow [3]. Treat the pattern as well supported and the precise numbers as the best available estimates.

What To Do With It

1. Check the value comparison before accepting any it was dying out story. Gallagher's method is simple: compare what the forced-labor sector was worth to everything else, as the 1860 census does [1]. Apply the same question to any claim that an exploitative system will fade on its own.

2. Separate cause from motivation when you read history. Ask both why a conflict happened and why ordinary people joined it, as Gallagher does with the Vermont farmer [1]. The answers are often different.

3. Keep your devices longer. Kara's personal takeaway is restraint: every phone, tablet and battery pulls cobalt, copper, lithium or tantalum from the same supply chain [2]. He quotes Gandhi: "live simply so that others may simply live." [2]

4. Don't assume a new chemistry or technology solves the problem. Kara warns that "cobalt-free" batteries, lithium from Manono and the metals in AI data centers all lead back to the same region and similar conditions [2]. Ask where the new material comes from.

5. Hold companies to cleanup, not just exit. Kara argues firms that profited must clean the water, restore farmland and build hospitals and schools, not simply stop buying [2]. Support demands for protective equipment and toxic-runoff containment, which he says are simpler than designing a smartphone [2].

6. Use the abolitionists' toolkit. The 1787 movement used viral images, testimony, investigative journalism and consumer boycotts [2]. Those tools are available to anyone today, and Kara sees a new movement forming around Congo [2].

7. Look for the enforcement mechanism, not just the moral argument. Cooper's game-theory point is that a trap breaks only when someone powerful enough enforces the rule [3]. When you support a reform, ask who will enforce it and whether buyers can simply switch to a less scrupulous supplier.

8. Watch for exploitation relabeled. Britain's "apprenticeship," shipped Indian laborers and underpaid immigrant workers show how forced labor can survive under a new name [2][3]. Ask whether a reform ends the practice or only changes what it is called.

9. Read the history of how people actually got here. Kara argues that Americans learn about plantations but not the ships, dungeons and finance behind them, and that this history "tells us why we are where we are" [2]. Remember too Cooper's warning that sources come mostly from the powerful, so seek out testimony from the people who did the work [3].

Sources

1. Gary Gallagher on the American Civil War: Slavery, Union, Lincoln, Grant, and Lee · Lex Fridman Podcast
2. Siddharth Kara on Congo's Cobalt Mines, AI's Hunger for Minerals, and The Zorg, the Slave Ship That Sparked Abolition · The Joe Rogan Experience
3. Darryl Cooper · The Joe Rogan Experience