During the American Revolution just about everyone in the thirteen colonies—or, after July 2, 1776,  the new United States—could be justly termed a traitor. For rebellious colonists prior to 1776, it was Parliament who had betrayed the English constitution. For royal officials, resistance and then rebellion was treason to the monarch. After independence, those who Americans identified numerous traitors in their midst—not only those who remained loyal to the old order of things, but even those who persisted a little too long in neutrality, or pacifism. As a legal issue, treason was in practice connected to numerous other things—to the power to arrest and detain; to the authority of the American  military; to the composition of juries; and to the meaning of citizenship.

With me to discuss the legal history of treason in the American Revolution is Carlton F.W. Larson, author of The Trials of Allegiance: Treason, Juries, and the American Revolution, published in 2019 by Oxford University Press. It is a legal history, but also a social history of how treason was defined, prosecuted, and adjudicated in the colony, and then the commonwealth, of Pennsylvania. Carlton Larson is Martin Luther King, Jr. Professor of Law at the Davis School of Law at the University of California Davis. A leading expert on the laws of treason, he has also just published On Treason: A Citizen’s Guide to the Law.