| Ex parte Milligan | |
|---|---|
 | |
| Argued March 5, 1866 Decided April 3, 1866 | |
| Full case name | Ex parte Lambdin P. Milligan |
| Citations | 71 U.S. 2 (more) |
| Case history | |
| Prior | This case came before the Court upon a certificate of division from the judges of the Circuit Court for Indiana, on a petition for discharge from unlawful imprisonment. |
| Holding | |
| Trying citizens in military courts is unconstitutional when civilian courts are still operating. Trial by military tribunal is constitutional only when there is no power left but the military, and the military may validly try criminals only as long as is absolutely necessary. | |
| Court membership | |
| |
| Case opinions | |
| Majority | Davis, joined by Clifford, Field, Grier, Nelson |
| Concur/dissent | Chase, joined by Wayne, Swayne, Miller |
| Laws applied | |
| U.S. Const., Habeas Corpus Suspension Act 1863 | |
Ex parte Milligan, 71 U.S. (4 Wall.) 2 (1866), is a landmark decision of the U.S. Supreme Court that ruled that the use of military tribunals to try civilians when civil courts are operating is unconstitutional. In this particular case, the Court was unwilling to give former President Abraham Lincoln's administration the power of military commission jurisdiction, part of the administration's controversial plan to deal with Union dissenters during the American Civil War. Justice David Davis, who delivered the majority opinion, stated that "martial rule can never exist when the courts are open" and confined martial law to areas of "military operations, where war really prevails", and when it was a necessity to provide a substitute for a civil authority that had been overthrown. Chief Justice Salmon P. Chase and three associate justices filed a separate opinion concurring with the majority in the judgment, but asserting that Congress had the power to authorize a military commission, although it had not done so in Milligan's case.
The case stemmed from a trial by a military commission of Lambdin P. Milligan, Stephen Horsey, William A. Bowles, and Andrew Humphreys that convened at Indianapolis on October 21, 1864. The charges against the men included, among others, conspiracy against the U.S. government, offering aid and comfort to the Confederates, and inciting rebellion. On December 10, 1864, Milligan, Bowles, and Horsey were found guilty on all charges and sentenced to hang. Humphreys was found guilty and sentenced to hard labor for the remainder of the war. (The sentence for Humphreys was later modified, allowing his release; President Andrew Johnson commuted the sentences for Milligan, Bowles, and Horsey to life imprisonment.) On May 10, 1865, Milligan's legal counsel filed a petition in the Circuit Court of the United States for the District of Indiana at Indianapolis for a writ of habeas corpus, which called for a justification of Milligan's arrest. A similar petition was filed on behalf of Bowles and Horsey. The two judges who reviewed Milligan's petition disagreed about the issue of whether the U.S. Constitution prohibited civilians from being tried by a military commission and passed the case to the U.S. Supreme Court. The case was argued before the Court on March 5 and March 13, 1866; the decision was handed down on April 3, 1866.