Ex parte Milligan (1866)

1) Link to the Actual Opinion
Read the U.S. Reports opinion (PDF)

2) Summary of the Opinion
Lambdin Milligan, a civilian in Indiana, was arrested during the Civil War and tried by a military tribunal for alleged disloyal activities. The Supreme Court held that trying civilians in military courts is unconstitutional when civilian courts are open and functioning.

3) Why It Mattered
This case set a powerful precedent protecting civil liberties during wartime. It declared that the Constitution applies “equally in war and in peace.”

4) What It Provided or Took Away

• Provided: Civilian supremacy over military authority in peacetime or where civil courts remain open.
• Took Away: The government’s claimed power to use military tribunals for civilians when normal courts are operating.

5) Overreach or Proper Role?
It was a strong judicial check on executive wartime power, but entirely within the Court’s role of upholding constitutional guarantees.

6) Plain-English Impact Today
Even during national emergencies, the government cannot bypass civilian courts and try people in military tribunals if the regular courts are available.

• Civil Liberties
• Military Tribunals
• Due Process
• Civil War Era
• Foundational