This Article III question has been debated in several of the nation’s major wars, yet remains unresolved, particularly with respect to the trial of domestic-law offenses. Moreover, that question is especially significant in the United States’ current armed conflicts against nonstate terrorist organizations, such as al Qaeda, both because members of such enemy forces, who lack international law “combatant immunity,” often violate U.S. criminal laws, and because Congress has recently authorized military commissions to try such enemy forces for certain domestic-law, war-related offenses. In attempting to justify the constitutionality of such military trials, the government has, perhaps surprisingly, turned to the Lincoln assassination commission as a leading precedent, one that arguably helps to establish a longstanding political branch practice that should inform constitutional understandings. Such reliance on the Lincoln trial as legal authority is understandable, because that proceeding was, in Judge Kavanaugh’s words, “the highest-profile and most important U.S. military commission precedent in American history,” and thus it would be striking — indeed, a significant constitutional embarrassment — to conclude that the trial and convictions of the Lincoln conspirators were unlawful.
As I demonstrate in this article, however, such respect for the Lincoln assassination trial as a canonical constitutional precedent would itself be historically anomalous. For almost 150 years it was virtually unthinkable for anyone to rely upon that proceeding as venerated legal authority: as one knowledgeable observer wrote, the Lincoln trial was a case of military jurisdiction that “no self-respecting military lawyer [would] look straight in the eye.”
This article offers the first comprehensive account of the ways in which the Article III question was contested during and immediately after the Civil War, with particular attention to the Lincoln assassination trial. The article also carefully examines the place of the Lincoln trial in the national constitutional discourse after 1868 — the ways in which that proceeding, and other Civil War military trials, have been accorded authority, or dismissed as nonauthoritative, by later generations. This broader historical narrative thus can help inform current academic and judicial debates about whether and under what circumstances political branch practice, especially high-profile precedents, ought to inform, or “liquidate,” the meaning or proper application of the Constitution.