1866 • Foundational

Ex parte Milligan

71 U.S. (4 Wall.) 2 (1866)

📄 Read the Actual Opinion

U.S. Reports opinion (PDF) →

📋 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.

⚖️ 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.”

✅ 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.

🤔 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.

💡 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.