Ex Parte Milligan

Ex parte Milligan, 71 U.S. 2 (1866), was a United States Supreme Court case that ruled that the application of military tribunals to citizens when civilian courts are still operating is unconstitutional.

Background of the case

Lambdin P. Milligan and four others were accused of planning to steal Union weapons and invade Union prisoner-of-war camps. Once the first prisoner of war camp was liberated they planned to use the liberated soldiers to help fight against the Government of Indiana and free other camps of Confederate soldiers. They also planned to take over the state governments of Indiana, Ohio, and Michigan. When the plan leaked, they were charged, found guilty, and sentenced to hang by a military court in 1864. However, their execution was not set until May 1865, so they were able to argue the case after the Civil War ended.

Arguments

The argument for the United States was delivered by Benjamin F. Butler, a Massachusetts lawyer and state legislator, and future Governor of Massachusetts.
The argument for the petitioner was delivered by Jeremiah S. Black, former Attorney General and Secretary of State, James A. Garfield, future President, and New York lawyer David Dudley Field.

The Supreme Court's Decision

The Supreme Court decided that the suspension of habeas corpus was lawful, but military tribunals did not apply to citizens in states that had upheld the authority of the Constitution and where civilian courts were still operating, and the Constitution of the United States provided for suspension of habeas corpus only if these courts are actually forced closed. In essence, the Court ruled that military tribunals could not try civilians in areas where civil courts were open, even during times of war.
It observed further that during the suspension of the writ of habeas corpus, citizens may be only held without charges, not tried, and certainly not executed by military tribunals. After all, the writ of habeas corpus is not the right itself but merely the ability to issue orders demanding the right's enforcement.

It is important to note the political environment of the decision. Post-war, under a Republican Congress, the Court was reluctant to hand down any decision that questioned the legitimacy of military courts, especially in the occupied South. The President's ability to suspend habeas corpus independently of Congress, a central issue, was not addressed probably because it was moot with respect to the case at hand. Though President Lincoln suspended the writ nationwide on September 24, 1862, Congress ratified almost six months later, on March 3, 1863. Milligan was detained in 1864, well after Congress formally suspended the writ. That notwithstanding, military jurisdiction had been limited

In this case, the Supreme Court granted the petitioner's request for discharge form unlawful imprisonment during the Civil War. The petitioner had been charged with conspiracy against the United States government; affording aid and comfort to rebels against authority of the United States; inciting insurrection; disloyal practices; and violation of the laws of war. In holding that a military commission was not competent to try the petitioner, the Court found it significant that the petitioner was a citizen not connected with military service and who lived in Indiana, was arrested there, and had not been a resident of any of the states in the rebellion or a prisoner of war. The petitioner had not been captured while participating in hostile activities against the government, for an offense against the United States. Thus, the Court held that the petitioner could not properly be tried on a criminal offense by a military commission, appointed by the military commander, in a state where the courts were open and unobstructed.