Jonathan Gienapp is an associate professor in the Law School and the History department. He received his B.A. from Harvard University and his Ph.D. from Johns Hopkins University. He specializes in the constitutional, political, legal, and intellectual history of the early United States. His primary focus to date has been the origins and development of the U.S. Constitution, in particular the ways in which Founding-era Americans understood and debated constitutionalism across the nation’s early decades. His historical interests intersect with modern legal debates over constitutional interpretation and theory, especially those centered on the theory of constitutional originalism.

His first book, The Second Creation: Fixing the American Constitution in the Founding Era (Harvard University Press, 2018), rethinks the conventional story of American constitutional creation by exploring how and why founding-era Americans’ understanding of their Constitution transformed in the earliest years of the document’s existence. More specifically, it investigates how early political debates over the Constitution’s meaning, in transforming the practices through which one could justifiably interpret the document, helped in the process alter how Americans imagined the Constitution and its possibilities. In the process, it considers how these changes created a distinct kind of constitutional culture, the consequences of which endure to this day. It won the 2017 Thomas J. Wilson Memorial Prize from Harvard University Press and the 2019 Best Book in American Political Thought Award from the American Political Science Association and was a finalist for the 2019 Frederick Jackson Turner Award from the Organization of American Historians. In addition, it was named a Choice Outstanding Academic Title for 2019 and a Spectator USA Book of the Year for 2018. It was reviewed in The Nation, was the subject of a symposium at Balkinization, and was chosen for the 2019 Publius Symposium co-hosted by the Stanford Constitutional Law Center and the Stanford Center for Law and History.

His second book, Against Constitutional Originalism: A Historical Critique (Yale University Press, 2024), presents a comprehensive historical critique of originalism. It argues that recovering Founding-era constitutionalism on its own terms fundamentally challenges originalists’ unspoken assumptions about the U.S. Constitution and its original meaning. The book builds on prior work on originalism and history, including his article, “Written Constitutionalism, Past and Present,” published in Law and History Review, which was identified as one of the best works of recent scholarship in constitutional law in a review at Jotwell and two essays that appeared on Process: A Blog for American History, published by the Organization of American Historians, that have been widely cited and discussed.

Gienapp is currently at work on a new book on the forgotten history of the Preamble to the U.S. Constitution, currently entitled “We the People of the United States: The Struggle over Popular Sovereignty and Nationhood.” It tells the story of the Preamble’s early vitality and eventual descent into political and legal irrelevance as a way of exploring the broader struggle over popular sovereignty and national union in the early United States.

In addition, Gienapp has published a range of articles, book chapters, and essays on early American constitutionalism, politics, and intellectual history, modern constitutional interpretation, and the study of the history of ideas in both historical journals and law reviews.

Gienapp has lectured widely on the U.S. Constitution and the American Founding era. He has been showcased in several National Constitution Center town halls and has been interviewed on the history of U.S. constitutionalism and politics in The New York Times and on NPR. He is a member of the Historians Council on the Constitution at the Brennan Center for Justice and has contributed to a number of historians’ amicus briefs to the Supreme Court of the United States. He is also one of the founding editors of the Journal of American Constitutional History where he serves as a senior editorial advisor.