On May 25, 1861, a secessionist named John Merryman was imprisoned by military order at Fort McHenry, Baltimore, Md., for his alleged pro-Confederate activities. Supreme Court Chief Justice Roger B. Taney, sitting as a federal circuit court judge, issued a writ of habeas corpus on the grounds that Merryman was illegally detained. General George Cadwalader, in command of Fort McHenry, refused to obey the writ, however, on the basis that President Abraham Lincoln had suspended habeas corpus.
Taney cited Cadwalader for contempt of court and then wrote an opinion about Article I, Section 9, of the Constitution, which allows suspension of habeas corpus “when in cases of rebellion or invasion the public safety may require it.” Taney argued that only Congress—not the president—had the power of suspension.
President Lincoln justified his action in a message to Congress in July 1861. More importantly, he ignored Taney’s opinion and adhered to the suspension of habeas corpus throughout the Civil War. Merryman, however, was later released. The constitutional question of who has the right to suspend habeas corpus, Congress or the president, has never been officially resolved.
Ex parte Merryman, 17 F. Cas. 144 (1861), is a well-known U.S. federal court case which arose out of the American Civil War. Against President Abraham Lincoln's wishes, Chief Justice Roger Taney, sitting as a judge of the United States Circuit Court for the District of Maryland, ruled: "1. That the president [...] cannot suspend the privilege of the writ of habeas corpus, nor authorize a military officer to do it. 2. That a military officer has no right to arrest and detain a person not subject to the rules and articles of war [...] except in aid of the judicial authority, and subject to its control."