Ex parte Milligan

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.

During the American Civil War, the administration of President Abraham Lincoln dealt with Union dissenters by declaring martial law; sanctioning arbitrary arrest and detention; suspending the writ of habeas corpus, which requires justification of any detention; and initiating trials by military commission rather than in conventional civil courts. The rationale for these actions was that Article 1, Section 9 of the U.S. Constitution authorizes the suspension of the writ of habeas corpus "when in Cases of Rebellion or Invasion the public Safety may require it". Lincoln theorized that the civil courts in the United States were established to try individuals and small groups "on charges of crimes well defined in the law" and not to deal with large groups of dissenters, whose actions, though damaging to the war effort, did not constitute a "defined crime" in states loyal to the government. Lincoln believed his administration's plan would suppress anti-government agitators, but he was also optimistic that it would be rescinded after the war ended.

The first test of Lincoln's thesis for silencing dissenters occurred in the spring of 1863. Clement Vallandigham, an Ohio politician and anti-war Democrat, was placed under arrest on May 5, 1863, taken to Cincinnati for a trial before a military commission, and jailed. Vallandigham was found guilty and sentenced to prison for the remainder of the war, but Lincoln commuted the sentence and ordered him exiled to the Confederacy. Vallandigham's petition to the U.S. Supreme Court, known as Ex parte Vallandigham, was denied.

The next test began with trials by a military commission that led to the U.S. Supreme Court case of Ex parte Milligan. On September 17, 1864, General Alvin Peterson Hovey, commander of the Military District of Indiana, authorized a military commission to meet on September 19 at Indianapolis, Indiana, to begin trials of Harrison H. Dodd, "grand commander" of the Sons of Liberty in Indiana, and others placed under military arrest. These prisoners included Democrats Lambdin P. Milligan, a lawyer living in Huntington, Indiana, and an outspoken critic of President Lincoln and Indiana's Republican governor Oliver P. Morton; Joseph J. Bingham, editor of the Indianapolis Daily Sentinel and chairman of Indiana's Democratic State Central Committee; William A. Bowles of French Lick, Indiana; William M. Harrison, secretary of the Democratic Club of Marion County, Indiana; Horace Heffren, editor of the Washington (Indiana) Democrat; Stephen Horsey of Martin County, Indiana; and Andrew Humphreys of Bloomfield, Indiana. Two other men, James B. Wilson and David T. Yeakel, were also seized. Dodd, who was the first to be tried, escaped from jail before his trial was completed and fled to Canada. On October 10, 1864, he was found guilty, convicted in absentia, and sentenced to hang. Charges against Bingham, Harrison, Yeakel, and Wilson were dismissed. Heffren was released before the proceedings against Milligan began.

The military commission for the trial of Milligan, Horsey, Bowles, and Humphreys convened in Indianapolis on October 21, 1864. The commission considered five charges against the men: conspiracy against the U.S. government, offering aid and comfort to the Confederates, inciting insurrections, "disloyal practices", and "violation of the laws of war". The defendants were alleged to have established a secret organization that planned to liberate Confederate soldiers from Union prisoner-of-war camps in Illinois, Indiana, and Ohio, and then seize an arsenal, provide the freed prisoners with arms, raise an armed force to incite a general insurrection, and join with the Confederates to invade Indiana, Illinois, and Kentucky and make war on the government of the United States.

The military commission's decision on December 10, 1864, found Milligan, Bowles, and Horsey guilty. The men were sentenced to be hanged on May 19, 1865. Humphreys was found guilty and sentenced to hard labor for the remainder of the war. With President Lincoln's support, General Hovey modified the sentence for Humphreys, allowing his release, but Humphreys was required to remain within two specific townships in Greene County, Indiana, and could not participate in any acts that opposed the war. Efforts were made to secure pardons for Milligan, Bowles, and Horsey, with the decision passing to President Johnson following Lincoln's assassination.

On May 10, 1865, Jonathan W. Gorden, Milligan's legal counsel, filed a petition for a writ of habeas corpus in the Circuit Court of the United States for the District of Indiana in Indianapolis. A similar petition was filed on behalf of Bowles and Horsey. The petitions were based on an act of the Congress titled "An Act Relating to Habeas Corpus and Regulation Judicial Proceedings in Certain Cases" that went into effect on March 3, 1863. The act was intended to resolve the question of whether Lincoln had the constitutional authority to suspend the writ of habeas corpus as authorized under Article 1, section 9, of the U.S. Constitution. Milligan's petition alleged that a federal grand jury had met in Indianapolis during January 1865, which it did, and it had not indicted him, which is also true, making him eligible for a release from prison under the congressional act.