The Revolutionary American Jury: A Case Study of the 1778-1779 Philadelphia Treason Trials

85 Pages Posted: 20 Mar 2008 Last revised: 6 Feb 2009

See all articles by Carlton F. W. Larson

Carlton F. W. Larson

University of California, Davis - School of Law

Date Written: March 18, 2008


Between September 1778 and April 1779, twenty-three men were tried in Philadelphia for high treason against the state of Pennsylvania. These trials were aggressively prosecuted by the state in an atmosphere of widespread popular hostility to opponents of the American Revolution. Philadelphia juries, however, convicted only four of these men, a low conviction rate even in an age of widespread jury lenity; moreover, in three of these four cases, the juries petitioned Pennsylvania's executive authority for clemency. Since it is unlikely that most of the defendants were factually innocent, these low conviction rates are a mystery that has never been adequately explained.

This Article offers such an explanation, and, in the process, uses these trials as a case study of jury service in late eighteenth-century America. We know surprisingly little about this important subject, as legal historians have focused almost exclusively on the more visible role of judges. Drawing on a wide variety of sources, this Article seeks to remedy this imbalance by providing the most thorough study yet written of a group of eighteenth-century American jurors.

The Article demonstrates, for the first time, how eighteenth-century American defense counsel creatively used peremptory challenges, deployed along religious, political, and economic lines, to create favorable juries, composed almost entirely of men who had previously served in treason cases. Through careful study of demographic records, this Article reconstructs the Philadelphia jury box and allows us to identify not only the social status of the jurors, but also the intricate network of connections linking the grand jurors, the trial jurors, and the defendants. It explains how Philadelphia jurors repeatedly balked at the death penalty, effectively nullifying Pennsylvania's capital law of treason. It also examines the subsequent attacks on jury independence triggered by these acquittals, ranging from strident newspaper criticism to a deadly militia attack on the home of James Wilson, signatory to the Declaration of Independence and defense counsel in many of the treason trials. By examining the actions of juries in a convulsive, violent civil war, the Article also illuminates the jury's historical role in balancing liberty and national security, an issue that continues to confront America today.

Keywords: legal history, jury, treason, Pennsylvania, American Revolution.

Suggested Citation

Larson, Carlton F. W., The Revolutionary American Jury: A Case Study of the 1778-1779 Philadelphia Treason Trials (March 18, 2008). Southern Methodist University Law Review, Vol. 61, No. 4, Fall 2008, UC Davis Legal Studies Research Paper, Available at SSRN:

Carlton F. W. Larson (Contact Author)

University of California, Davis - School of Law ( email )

Martin Luther King, Jr. Hall
Davis, CA CA 95616-5201
United States

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