Milligan, Ex Parte (1866).The case, Milligan 71 U.S. 2 (1866), brought to the U.S. Supreme Court fundamental questions regarding military authority over civilians. In 1864, a military commission in Indiana during the Civil War convicted Lambdin P. Milligan on charges of conspiracy for his part in an alleged plot to release and arm Confederate prisoners in Northern prison camps and sentenced him to death. Milligan appealed to the civil courts, challenging the military tribunal's jurisdiction over his case. When the case reached the Supreme Court in 1866, the justices unanimously ordered Milligan's release. In the majority opinion for the Court, Justice David Davis held that the Constitution prohibited military trials of civilians where civil courts remained open. Martial law was only permissible, he insisted, in “the theater of active military operations,” where civil courts could no longer function. In a concurring opinion joined by three other justices, Chief Justice Salmon P. Chase argued that Congress intended to ensure civil trials to civilians when it adopted the Habeas Corpus Act of 1863, and therefore Milligan had been wrongly tried. However, unlike Davis, Chase insisted that Congress under its war powers had the authority to enact martial law, even in areas removed from the theater of war.

Milligan promptly provoked criticism from those who feared that it compromised Republican Reconstruction plans for the South by restricting military authority over civilians. Although in the twentieth century the Supreme Court has been reluctant to endorse Milligan's wholesale ban on martial law outside the theater of war, the case has never been reversed and scholars continue to hail it as a landmark constitutional protection of civil rights.
[See also Civil Liberties and War; Civil‐Military Relations: Civilian Control of the Military; Merryman, Ex Parte; Supreme Court, War, and the Military.]

Bibliography

Harold M. Hyman and and William M. Wiecek , Equal Justice Under Law: Constitutional Development, 1835–1875, 1982.
Mark E. Neely, Jr. , The Fate of Liberty: Abraham Lincoln and Civil Liberties, 1991.

Mary J. Farmer