Matthew Karp is Assistant Professor of History and Elias Boudinot Bicentennial Preceptor at Princeton University. His book This Vast Southern Empire: Slaveholders at the Helm of American Foreign Policy (2016) was co-winner of the James Broussard Best First Book Prize.

The Republic (TR). For those who haven’t read your book, would you please provide a synopsis?
Matthew Karp (MK): The book explores the ways that southern slaveholders directed U.S. foreign policy in the decades before the Civil War. Slaveholders were overrepresented in every branch of the antebellum federal government, but as presidents, cabinet officers, congressional committee chairmen, and diplomats, they were especially dominant in the realm of foreign and military policy. After the shock of British emancipation in the Caribbean, the book argues, antebellum southern elites came to understand the United States as the western hemisphere’s leading champion of slavery. Slaveholders embraced an assertive, even aggressive foreign policy that mustered the full force of the federal government to help protect slave property across the hemisphere, from Texas to Cuba to Brazil. The antebellum era’s most ambitious military reformers were proslavery leaders like Secretary of the Navy Abel Upshur of Virginia and Secretary of War Jefferson Davis of Mississippi. Far from isolated reactionaries, decrying the advance of modernity, America’s most powerful slaveholders were confident that slavery — by the 1850s, more extensive and more prosperous than ever — was fully compatible with modern development on a global scale. Only the victory of Abraham Lincoln and the antislavery Republican Party in 1860 convinced southern elites to abandon the United States and found their own independent slaveholding republic.

TR: What led you to choose this topic for your book?
MK: It goes back a while. As an undergraduate, my favorite courses were on 20th century U.S. foreign policy — with class discussions that pivoted on the great ideological and strategic struggles of the 20th century, between fascism, communism, and capitalism. It occurred to me that not many people wrote about 19th century foreign relations in the same terms, even though the struggle over slavery was in some ways just as epochal and just as international. I did my undergraduate thesis on slavery, antislavery and the British response to the U.S. annexation of Texas. In graduate school, working with two historians of the South (Steven Hahn and Stephanie McCurry), I decided to focus more explicitly on the South and foreign policy. That led pretty directly to the foreign policy of slavery.

TR: Which historians and/or writers most influenced your research for this book?
MK: That would be a long list — and my endnotes probably tell the story more eloquently than anything I can say here. But to zoom out for a bit, my list should probably begin with W.E.B. DuBois, whose writings on Atlantic slavery and the Civil War era built a kind of foundation for the way we understand these things in the 21st century, even as his work was marginalized by the academy during his lifetime. The book’s epilogue is built around Du Bois’s commencement address at Harvard in 1890, which bore the provocative title “Jefferson Davis as a Representative of Civilization.” Another legendary historian who thought in very large terms, and whose work I find myself returning to again and again, is Eric Hobsbawm. His influence on the book I think is apparent — even, or perhaps especially, when I disagree with him.

Of course, the book was also shaped by the more recent outpouring of scholarship that approaches the early American republic (and American slavery) in international terms. Rather than tick off an endless list of names, I’ll single out two younger historians whose work had a concrete influence on my own. I was thrilled to share the Broussard prize with Caitlin Fitz, whose research on US attitudes toward Latin American revolutions helped me frame and periodize my early chapters, on the emergence of a distinctively proslavery foreign policy after British emancipation. And Brian Rouleau, whose work I’ve cribbed from since grad school, helped me think about US foreign relations not just in terms of armies and territories, but steamships and oceans.

TR: Many Americans seem to accept the notion that the South was a marginalized region that threw off northern oppression in the secession winter of 1860-61. Why do you think that idea persists, despite the voluminous scholarship that historians have produced that shows otherwise?
MK: It’s an interesting question. Part of the problem, I think, is that often this is really a political battle masquerading as a historical debate. For some people, idea of an oppressed antebellum South — fighting off a bullying Northern overdog — has come to play an important role in their own personal and political identities. It’s sort of a proxy war for more complex contemporary struggles, involving race, class, and region. In that sense, I think historians are kidding themselves if they think that these questions can be resolved, or even advanced, by a non-partisan appeal “to the facts.” To the extent that this is a political struggle, it has to be fought politically. That means appealing to people with arguments that resonate with their everyday lives, not brandishing documentary evidence that proves something about secession, however definitive. I’m not saying we should stop making historical arguments — it’s our job to get the facts right, which means rejecting the bogus narrative of Southern oppression — but I don’t think we should kid ourselves that facts alone will move the ball. The climate change battle is another reminder of this.

Tracing the intellectual genealogy of that idea is somewhat easier. The notion that the South was “marginalized” before 1860, I think, really only takes off after the end of the Civil War, when ex-Confederates like Jefferson Davis and Alexander Stephens composed their long and self-serving histories of the rebellion. For a long time, historians continued to look at the antebellum South from the perspective of Appomattox — consciously or unconsciously using the South’s wartime defeat as a way to emphasize southern weakness before the war. My book joins a host of recent scholarship that thinks we should examine the master class from the perspective of Washington DC, where antebellum southerners actually dominated American politics.

TR: What is your current/next project?
MK: I’ve begun work on a book tentatively called The Radicalism of the Republican Party. Spending a dozen years with proslavery southerners has only underlined my feeling that the national victory of an anti-slavery party in 1860 was a surprising and transformative moment in American political history. After all the recent scholarship re-emphasizing the strength and power of the antebellum master class, I think we need to reconsider the origins, growth, and worldview of the party organization that overthrew that class.