By 1830, one million Americans, most of them enslaved, grew cotton. Raw cotton was the most important export of the United States, at the center of America’s financial flows and emerging modern business practices, and at the core of its first modern manufacturing industry. As John Brown, a fugitive slave, observed in 1854: “When the price [of cotton] rises in the English market, the poor slaves immediately feel the effects, for they are harder driven, and the whip is kept more constantly going.”

Just as cotton, and with it slavery, became key to the U.S. economy, it also moved to the center of the world economy and its most consequential transformations: the creation of a globally interconnected economy, the Industrial Revolution, the rapid spread of capitalist social relations in many parts of the world, and the Great Divergence—the moment when a few parts of the world became quite suddenly much richer than every other part.

The humble fiber, transformed into yarn and cloth, stood at the center of the emergence of the industrial capitalism that is so familiar to us today. Our modern world originates in the cotton factories, cotton ports, and cotton plantations of the 18th and 19th centuries. The United States was just one nexus in a much larger story that connected artisans in India, European manufacturers, and, in the Americas, African slaves and land-grabbing settlers. It was those connections, over often vast distances, that created an empire of cotton—and with it modern capitalism.

To understand American slavery it is not enough to just look at the United States itself. We need to broaden our view to the world at large and to the history of global capitalism as it unfolded over several centuries. To understand American slavery we need to analyze the relative strength of social and political structures in places such as the 18th-century Ottoman Empire and 1840s western India. To understand capitalism’s relationship to slavery, we need to see the control of cultivators in Africa over their land and labor, as well as the transformations of the Indian countryside, the institutional structures of capitalism in Britain, and the state structures of Egypt.

It is at this point that the history of capitalism connects in refreshing ways with another important emerging field, global history. As is widely known, history as an academic discipline emerged hand-in-hand with the modern nation-state, and indeed played an important part in its constitution. It is for this reason that most history has been framed within the borders of modern states. In recent years, however, some historians have tried to think beyond such frameworks, bringing together stories of regional or even global scope—for example, Charles S. Maier’s Leviathan 2.0: Inventing Modern Statehood and Jürgen Osterhammel’s The Transformation of the World: A Global History of the Nineteenth Century.

Within that literature, economic history has played a particularly important role, with trailblazing works such as Kenneth Pomeranz’s The Great Divergence: China, Europe, and the Making of the Modern World Economy, and Marcel van der Linden’s Workers of the World: Essays Toward a Global Labor History. Economic history, which for so long has been focused mostly on “national” questions—the “coming of managerial capitalism” in the United States, “organized capitalism” in Germany, the “sprouts of capitalism” in China—now increasingly tackles broader questions, looking at capitalism as a global system.

When we apply that global perspective, we develop a new appreciation for the centrality of slavery, in the United States and elsewhere, in the emergence of modern capitalism. We can also comprehend how that dependence on slavery was eventually overcome later in the 19th century. We come to understand that the ability of European merchants to secure ever-greater quantities of cotton cloth from South Asia in the 17th and 18th centuries was crucial to the trans-Atlantic slave trade, as cloth came to be the core commodity exchanged for slaves on the western coast of Africa. We grasp that the rapidly expanding markets for South Asian cloth in Europe and elsewhere motivated Europeans to enter the cotton-manufacturing industry, which had flourished elsewhere in the world for millennia.

And a global perspective allows us to comprehend in new ways how slavery became central to the Industrial Revolution. As machine production of cotton textiles expanded in Britain and continental Europe, traditional sources of raw cotton—especially cultivators in the Ottoman Empire as well as in Africa and India—proved insufficient. With European merchants unable to encourage the monocultural production of cotton in these regions and to transform peasant agriculture, they began to draw on slave-grown cotton, at first from the West Indies and Brazil, and by the 1790s especially in the United States.

As a result, Europe’s ability to industrialize rested at first entirely on the control of expropriated lands and enslaved labor in the Americas. It was able to escape the constraints on its own resources—no cotton, after all, was grown in Europe—because of its increasing and often violent domination of global trade networks, along with the control of huge territories in the Americas. For the first 80 years of modern industry, the only significant quantities of raw cotton entering European markets were produced by slaves—and not from the vastly larger cotton harvests of China or India.

When we marshal big arguments about the West’s superior economic performance, and build these arguments upon an account of the West’s allegedly superior institutions like private-property rights, lean government, and the rule of law, we need to remember that the world Westerners forged was equally characterized by exactly the opposite: vast confiscation of land and labor, huge state intervention in the form of colonialism, and the rule of violence and coercion.

By 1800, 25 percent of the cotton that landed in Liverpool, the world’s most important cotton port, originated in the United States; 20 years later, that proportion had increased to 59 percent; by 1850, 72 percent of the cotton consumed in Britain was grown in the United States, with similar proportions for other European countries.

A global perspective lets us see that the ability to secure more and cheaper cotton gave European and North American manufacturers the ability to increase the production of cheap yarn and cloth, which in turn allowed them to capture ancient cotton markets in Asia, Africa, and elsewhere, furthering a wave of deindustrialization in those parts of the world. Innovations in long-distance trade, the investment of capital over long distances, and the institutions in which this new form of capitalist globalization were embedded all derived from a global trade dominated by slave labor and colonial expansion.

A global perspective on the history of cotton also shows that slave labor is as much a sign of the weakness as of the strength of Western capital and states. The ability to subdue labor in distant locations testified to the accumulated power of European and North American capital owners. Yet it also showed their inability to transform peasant agriculture. It was only in the last third of the 19th century that peasant producers in places such as Central Asia, West Africa, India, and upcountry Georgia, in the United States, could be integrated into the global empire of cotton, making a world possible in which the growing of cotton for industry expanded drastically without resort to enslaving the world’s cotton workers. Indeed, one of the weaknesses of a perspective that focuses almost exclusively on the fabulously profitable slave/cotton complex of the antebellum American South is its inability to explain the emergence of an empire of cotton without slavery.

We cannot know if the cotton industry was the only possible way into the modern industrial world, but we do know that it was the path to global capitalism. We do not know if Europe and North America could have grown rich without slavery, but we do know that industrial capitalism and the Great Divergence in fact emerged from the violent caldron of slavery, colonialism, and the expropriation of land. In the first 300 years of the expansion of capitalism, particularly the moment after 1780 when it entered into its decisive industrial phase, it was not the small farmers of the rough New England countryside who established the United States’ economic position. It was the backbreaking labor of unremunerated American slaves in places like South Carolina, Mississippi and Alabama.

When we marshal big arguments about the West’s superior economic performance, and build these arguments upon an account of the West’s allegedly superior institutions like private-property rights, lean government, and the rule of law, we need to remember that the world Westerners forged was equally characterized by exactly the opposite: vast confiscation of land and labor, huge state intervention in the form of colonialism, and the rule of violence and coercion. And we also need to qualify the fairy tale we like to tell about capitalism and free labor. Global capitalism is characterized by a whole variety of labor regimes, one of which, a crucial one, was slavery.

During its heyday, in fact, slavery was seen as essential to the economy of the Western world. No wonder the British journal The Economist worried in September 1861, when Union General John C. Frémont emancipated slaves in Missouri, that such a “fearful measure” might spread to other slaveholding states, “inflict[ing] utter ruin and universal desolation on those fertile territories”—and on the merchants of Boston and New York, “whose prosperity … has always been derived” to a large extent from those territories.

Slavery did not die because it was unproductive or unprofitable, as some earlier historians have argued. Slavery was not some feudal remnant on the way to extinction. It died because of violent struggle, because enslaved workers continually challenged the people who held them in bondage—nowhere more successfully than in the 1790s in the French colony of Saint-Domingue (now Haiti, site of the first free nation of color in the New World), and because a courageous group of abolitionists struggled against some of the dominant economic interests of their time.

A contributing factor in the death of slavery was the fact that it was a system not just of labor exploitation but of rule that drew in particular ways on state power. Southern planters had enormous political power. They needed it: to protect the institution of slavery itself, to expand its reach into ever more lands, to improve infrastructures, and to position the United States within the global economy as an exporter of agricultural commodities.

In time, the interests of the South conflicted more and more with those of a small but growing group of Northern industrialists, farmers and workers. Able to mobilize labor through wage payments, Northerners demanded a strong state to raise tariffs, build infrastructures conducive to domestic industrialization, and guarantee the territorial extension of free labor in the United States. Afraid that they were losing control over essential levers of power, slaveowners tried to strike out on their own.

Slavery did not die because it was unproductive or unprofitable, as some earlier historians have argued. Slavery was not some feudal remnant on the way to extinction.

After the Civil War, a new kind of capitalism arose, in the United States and elsewhere. Yet that new capitalism—characterized first and foremost by states with unprecedented bureaucratic, infrastructural, and military capacities, and by wage labor—had been enabled by the profits, institutions, networks, technologies, and innovations that emerged from slavery, colonialism and land expropriation.

That legacy is still with us today. The great inequalities, both domestically and internationally, that characterize the world we live in are at least partly the result of capitalism’s long and violent history.

There are still many open questions about slavery and capitalism, some specific, some broad. We have not yet conclusively shown, for example, if and how methods of labor control migrated from the world of the plantation to the world of the factory. We need more-detailed research on where the profits from slavery accumulated in Europe and the American North, and how they mattered to other sectors of the economy. We would benefit from a better understanding of how the tight economic connection between Northern entrepreneurs and slavery came to be undone. And we have only begun to account for what the rethinking of slavery does to our more general understanding of capitalism.

But what we do know is that the histories of slavery and of capitalism look very different if we understand them in relation to each other. The next time we walk the streets of Lower Manhattan, the docks of Liverpool or the grounds of Harvard University, we should think at least in passing of the millions of enslaved workers who helped make some of that grandeur possible, and to the ways that slavery’s legacy persists today.

Sven Beckert is a professor of American history at Harvard University. His latest book, “Empire of Cotton: A Global History,” has just been published by Alfred A. Knopf.