## Facts

- John Merryman, a Maryland militia officer, was arrested by Union forces in May 1861 for alleged treasonous acts, including disrupting rail and telegraph lines.
- Merryman was detained at Fort McHenry under military authority without a civilian warrant or prompt presentation to a civil court.
- During the early Civil War, the President had authorized military commanders to suspend habeas corpus along a key transportation corridor for public safety.
- Merryman petitioned for a writ of habeas corpus; the circuit justice issued the writ ordering the fort’s commander, Gen. George Cadwalader, to produce Merryman in court.
- Cadwalader refused to produce Merryman, asserting that Merryman was held on a treason charge under presidential authorization to suspend the writ.
- The court issued an attachment for contempt, but the marshal was denied entry to the fort and could not serve process.
- The circuit justice filed a written opinion and directed that it be transmitted to the President; the Executive did not comply, and Merryman was later released on bail without prosecution.

## Issues

1. Whether the President may suspend the privilege of the writ of habeas corpus absent an act of Congress.
2. Whether military officers may arrest and detain a civilian for alleged federal offenses outside ordinary judicial process and control.

## Decision

- The circuit justice concluded that the privilege of the writ of habeas corpus may be suspended only by Congress, not by the President, and not by presidential delegation to military officers.
- The court stated that military detention of civilians for alleged violations of federal law is lawful only in aid of civil authority and subject to judicial control, with the detainee to be promptly delivered to civil authorities.
- On the record presented, the court determined Merryman was entitled to immediate release from military confinement.
- Although the court attempted contempt enforcement, it acknowledged it lacked practical power to execute process against the fortified military custodian when the military refused service.

## Legal Principles

- The Suspension Clause is a constitutional limitation placed in Article I; suspension of habeas corpus requires legislative authorization.
- The President’s duty to ensure faithful execution of the laws does not include unilateral authority to suspend constitutional privileges or to authorize military officers to disregard judicial process.
- Military authority over civilians is constrained: absent lawful judicial process or a role supporting civil enforcement, military officers lack power to arrest and continue detaining civilians for domestic offenses.
- Courts retain the duty to declare what the law requires even when other branches refuse compliance; noncompliance primarily affects enforcement, not the legal determination.

## Conclusion

The court held that suspending habeas corpus is a power reserved to Congress and that the military may not detain civilians beyond the supervision of the civil courts; the ruling ordered Merryman’s release but exposed limits on judicial enforcement when the Executive and military refused to comply.


Ex parte Merryman, 17 F. Cas. 144 (C.C.D. Md. 1861)