For many years, the consensus view of American slavery has been that of a historical anomaly in an idealistic country that knew better, an inefficient business model that propped up the South as the industrial North galloped into modernity, and a painful speedbump on America’s road to becoming a global economic power.

In The Half Has Never Been Told: Slavery and the Making of American Capitalism, a substantial new history—possibly the most important work on slavery in a generation—Cornell historian Edward E. Baptist finds slavery to be the major force driving the American economy and the predominant factor that catapulted America onto the world stage in the first half of the 19^th century.

“In fact, slavery’s expansion shaped every crucial aspect of the economy and politics of the new nation,” Baptist writes. “The idea that the commodification and suffering and forced labor of African Americans is what made the United States powerful and rich is not an idea that people necessarily are happy to hear. Yet it is the truth.”

I spoke recently to Baptist about his new book, his research, and how views of slavery’s role in the American economy have changed over time.

Why focus on slavery instead of something more current like the civil rights movement in the 1960s or pan-African nationalism in the 1970s?

One question that started when I was reading African history as an undergrad was what was the role of slavery in shaping the world that we live in today? I began to suspect that it had had a very determinative effect on the shape of American politics, American society, American culture, and the American economy.

The point about the economy was interesting. We were always told that slavery wasn’t particularly profitable or didn’t have a big influence on the industrial revolution, and yet slavers stuck with slavery for a very long time. They seemed to be making a lot of money. They seemed to be selling these commodities that were tremendously important to the economy. People seemed to be very willing to invest money in their enterprises. So something didn’t seem quite right to me. I wanted to get to the bottom of that.

I was able to spend a whole summer and then a year delving through the records—hundreds of plantation families—at the Southern Historical Collection at UNC — and what I found was that the bulk of those records were business records of the financing, production, and selling of cotton.

Isn’t that where the tension came from—the industrial economy of the North and the agrarian economy of the South? That those differences weren’t conducive to slavery continuing indefinitely?

If you look at the pre-Civil War economy, you see cotton is tremendously important to the North as well as the South. Shipping cotton, spinning and weaving it into cloth, investing money in its production—all these things are crucial to the North’s economy. For a long, long time—until about 1850—the cotton-related functions the North is carrying out to finance and move southern cotton to the world market are bigger than industrial production in the North. Most of that cotton ends up in Britain, which is the big industrial power of the pre-Civil War, pre-1900 world. Slavery, as I looked closer and closer, turned out to be much more economically dynamic than I thought.

How much did the northern economy depend on the South?

Northern economic growth piggy-backed on southern economic growth, and southern economic growth was built on the expansion of cotton production. Southern plantations after the American Revolution were economically in trouble because the commodities they made were commanding a very low price on the international market. But northern economies were in trouble because they didn’t have products they could sell on the international market. So the discovery of ways to move and make cotton more efficiently is tremendously important for the whole American economy. I would argue that it’s the secret of the American economy’s rapid expansion.

Do you see the South before the Civil War as akin to other periods of wealth concentration like the Golden Age or even today?

That’s an interesting question. If you look at Thomas Piketty’s recent book, he probably doesn’t think carefully enough about slavery. But you see the South with a wealth profile in the 1830s, ‘40s, and ‘50s that’s very similar to what you see in Western Europe at the same time or what you see in the United States today. If you look only at whites—enslaved people were excluded from most economic activity—six of the seven wealthiest states per capita in the U.S. in 1860 are cotton states. The South is the center of gravity of wealth concentration in the U.S.

To the extent that the study of history is oriented toward analyzing and solving problems, do you think these things have less significance the further you go back in time?

The problem is that we don’t want to acknowledge slavery’s impact. We have not come to terms with the way it has shaped the distribution of wealth in America—not just between white and black, but even in different regions and even among whites. I can’t tell you what that coming to terms would look like, but I believe it starts with telling the truth and acknowledging what happened in slavery—acknowledging that this was really important, that a lot of people profited, that a lot of that wealth is still around, and that’s it’s still shaping people’s lives today.

Are you more interested in this material as pure research or because it says something about the contemporary condition?

I have to straddle that. One of the things I have to do at the root of the book in terms of how I structure it operate on the assumption that people who are dead but have left their words behind are still communicating with us and we may hear them differently in different generations. As historians, we have a responsibility to get those stories out there. I engage in particular with the testimonies left behind of people who survived slavery, whether they wrote them down like Frederick Douglass or were interviewed in the 1930s as a lot of elderly ex-slaves were. They tell us many things that are tremendously important about shaping the present.

If you want to understand how our economy became very dynamic and grew rapidly over time, you have to look at slavery and cotton plantations. If you want to understand why our economy is leaving lots of people behind, we also have to look at the influence of slavery in creating that kind of pattern—that idea that growth, profit, progress are more important than other values. That’s something we struggle with in our society.

Scott Porch is an attorney and contributing writer for Kirkus Reviews and The Daily Beast. He is writing a book about social upheaval in the 1960s and '70s.