Ex parte Milligan 1866

Could a civilian be tried by military commission where civilian courts were open?

71 U.S. 2 (1866)War and national security

The question: Could a civilian be tried by military commission where civilian courts were open?
What the Court held: No. Military trial of civilians is unconstitutional where the civil courts are open and functioning, even in wartime.
The vote: 9–0. Unanimous on the judgment; 5–4 on whether Congress itself could have authorized such trials.
Era: Reconstruction
Read the opinion: 71 U.S. 2 (1866), full text

This page summarizes the Court’s judgment in neutral terms. The opinion, concurrences and dissents are the authority; read them for the reasoning.

Where the question came from. The events behind it.

1861

Lincoln authorizes suspension of habeas corpus

April 27, 1861 · Emergency and war powers

At the start of the Civil War, President Lincoln authorizes military commanders to suspend the writ along the rail line between Philadelphia and Washington. Chief Justice Taney, sitting as a circuit judge in Ex parte Merryman, rules that only Congress may suspend it. Congress authorizes suspension in March 1863.

Source: Federal Judicial Center