At the dawn of the twentieth century, the United States was reeling from the effects of rapid urbanization and industrialization. Time-honored verities proved obsolete, and intellectuals in all fields sought ways to make sense of an increasingly unfamiliar reality. The legal system in particular began to buckle under the weight of its anachronism. In the midst of this crisis, John Henry Wigmore, dean of the Northwestern University School of Law, single-handedly modernized the jury trial with his 1904-5 Treatise on evidence, an encyclopedic work that dominated the conduct of trials. In so doing, he inspired generations of progressive jurists—among them Oliver Wendell Holmes, Jr., Benjamin Cardozo, and Felix Frankfurter—to reshape American law to meet the demands of a new era. Yet Wigmore’s role as a prophet of modernity has slipped into obscurity. This book provides a radical reappraisal of his place in the birth of modern legal thought.