Ex parte Merryman, 17 F. Cas. 144 (C.C.D. Md. 1861) (No. 9487), was a controversial U.S. federal court case during the American Civil War.McGinty (2011) p. 173; Neely (2011) p. 65. It was a test of the authority of the President to suspend "the privilege of the writ of habeas corpus" under the Constitution's Suspension Clause, when Congress was in recess and therefore unavailable to do so itself.William H. Rehnquist, All the Laws But One (New York: Knopf, 1998), pp. 27-39. Generally, the case raised questions about the ability of the executive branch to decline to enforce judicial decisions when the executive believes them to be erroneous and harmful to its own legal powers.

John Merryman was a prominent planter from Baltimore County, Maryland, who had been arrested at his rural plantation for destroying railroad bridges on which Union troops were traveling. Held prisoner in Fort McHenry in Baltimore harbor,Fort McHenry had been nicknamed the "Baltimore Bastille" for its large numbers of Southern sympathizers under summary arrest held captive in the "Star Fort", while Congress was in recess that Spring of 1861. he was kept incommunicado to judicial and to civilian legal authorities. While riding circuit, Chief Justice Roger B. Taney ruled that the authority to suspend habeas corpus lay exclusively with Congress.

Taney filed the Merryman decision with the United States Circuit Court for the District of Maryland, but it is unclear whether Taney's decision was a circuit court decision. One view, based in part on Taney's handwritten copy of his decision in Merryman, is that Taney heard the habeas action under special authority granted to federal judges by Section 14 of the Judiciary Act of 1789. According to this view, Merryman was an in-chambers opinion."One significant point of disagreement among historians and political scientists is whether Roger Taney heard Ex parte Merryman as a U.S. circuit judge or as a Supreme Court justice in chambers." White, Jonathan W., Abraham Lincoln and Treason in the Civil War: The Trials of John Merryman, Baton Rouge: Louisiana State University Press, 2011, pp. 38–39. Due to its vague jurisdictional locus and hastened disposition, aspects of the Merryman decision remain contested.See Bruce A. Ragsdale, Ex parte Merryman and Debates on Civil Liberties During the Civil War, pages 11 & 15 (Federal Judicial History Office 2007). Federal Judicial CenterSeth Barrett Tillman, "Ex parte Merryman: Myth, History, and Scholarship", 224 Military Law Review 481 (2016)

The executive branch, including the United States Army, under the authority of the President of the United States as Commander-in-Chief, did not comply with the Merryman decision. Weeks later, Merryman was released on bail without further prosecution. In 1863, Congress passed the Habeas Corpus Suspension Act to cure the constitutional defect.

Background When a person is detained by police or other authority, a court can issue a writ of habeas corpus, compelling the detaining authority either to show proper cause for detaining the person (e.g., by filing criminal charges) or to release the detainee. The court can remand the prisoner to custody, release them on bail, or release them outright. Article I, Section 9 of the United States Constitution, which prescribes and limits the power of Congress, includes the Suspension Clause:

The Privilege of the Writ of Habeas Corpus shall not be suspended, unless when in Cases of Rebellion or Invasion the public Safety may require it.

In April 1861, when combat erupted in the Civil War, President Abraham Lincoln called for the states to provide militia troops to the Federal government to suppress the rebellion. Troops traveling to Washington passed through Baltimore, Maryland. Baltimore mobs objecting to a war with the seceding states attacked some of the troop transports on April 19. It seemed possible that Maryland would attempt to block the passage of troops, cutting off Washington and impeding a war against the South.

On April 29, the Maryland legislature voted 53–13 against secession,Mitchell, p.87 but it also voted not to reopen rail links with the North. It requested that Lincoln remove the growing number of federal troops from Maryland. At this time the legislature appeared to want to avoid involvement in a war with its southern neighbors. Fearful that the transport of more Union troops through the city and state would provoke more rioting, and possibly in an attempt to enact secession by extralegal means, Mayor George Brown of Baltimore and Governor Thomas Hicks of Maryland asked that no more troops cross Maryland, but Lincoln refused. For the next few weeks, troops were transported to Washington via Annapolis, avoiding Baltimore. Also on April 19, Lincoln asked Attorney General Edward Bates for an opinion on the suspension of the writ of habeas corpus.

The threat to the capital was serious, and Lincoln responded by delegating limited authority to the Army to suspend habeas corpus in Maryland. On April 27, 1861, he told General Winfield Scott (commanding general of the Army) that if there was any resistance on the "military line" from Annapolis to Washington, Scott or "the officer in command at the point" was authorized to suspend habeas corpus if necessary.

Following the Maryland legislature's April 29 directive that Maryland not be used as a passage for troops attacking the South, Governor Hicks allegedly ordered the state militia to demolish several state railroad bridges (at Bush River and Gunpowder River). Militia Lieutenant John Merryman was arrested on May 25 by order of Brigadier General William High Keim of the United States Volunteers, for his role in destroying the bridges. Merryman was charged with treason and being a commissioned lieutenant in an organization intending armed hostility toward the government.Tucker, Spencer C. American Civil War: The Definitive Encyclopedia, 2013. p. 1269

In another Maryland habeas corpus case, just prior to Merryman, Judge William Fell Giles of the United States District Court for the District of Maryland issued a writ of habeas corpus, which was ignored by the commander of Fort McHenry, Major William W. Morris.Benson John Lossing (1866/1997), Pictorial Field Book of the Civil War, reprint, Baltimore: Johns Hopkins, Vol. I, Chap. XVIII, "The Capital Secured – Maryland Secessionists Subdued – Contributions by the People", pp. 449–450 [italics in reprint].

Rather than approaching Judge Giles, Merryman's lawyers went to Washington, D.C., and asked Chief Justice Taney to issue a writ of habeas corpus. Taney promptly issued the writ on Merryman's behalf on May 26, 1861; Taney ordered General George Cadwalader, the commander of the military district including Fort McHenry, where Merryman was being held, to bring Merryman before Taney the next day. Taney's order directed Cadwalader only to produce Merryman at court, not to release him. During that era, Supreme Court Justices sat as circuit court judges, as well. It is unclear if Taney was acting in his role as a circuit judge for the United States Circuit Court for the District of Maryland, or making use of special authority to hear habeas matters permitted to all federal judges, including the Chief Justice, under Section 14 of the Judiciary Act of 1789.

Taney stated that he held court on this matter in Maryland, rather than Washington, D.C., in order to permit Gen. Cadwalader to answer the writ in Baltimore rather than the capital, and so not to have to leave the limits of his military command.

Cadwalader, although a lawyer, had less than one day to draft a response and defense for his conduct and that of the Army. Cadwalader responded to Taney's order on May 27 by sending a colonel to explain that the Army had suspended the writ of habeas corpus under presidential authority. Cadwalader also provided a letter explaining the circumstances of Merryman's arrest, including that Merryman was arrested by Keim's subordinates for treason, and for being illegally in possession of U.S. arms, and for advocating "armed hostility against the Government". The letter declared that the public safety was still threatened and that any errors "should be on the side of safety to the country". Because of the serious nature of the charges and complexity of the issues, Cadwalader requested an extension to reply in order to get further instructions from the President.

Taney refused the requestMcGinty (2011) pp. 85–86 and instead held Cadwalader in contempt of court for refusing to produce Merryman.Dirck, Brian. Lincoln and the Constitution, p. 79 (Southern Illinois University Press, 2012).McGinty, Brian. The Body of John Merryman, p. 13 (Harvard University Press 2011). Accordingly, Taney issued a writ of attachment for Cadwalader, ordering a U.S. Marshal to seize Cadwalader and bring him before the court the following day.

Cadwalader had been sent instructions on May 28, 1861, from Army headquarters explicitly acknowledging issuance of the writ by Taney and ordering Cadwalader, under the President's authority, to keep Merryman in custody.The War of the Rebellion: A Compilation of the Official Records of the Union and Confederate Armies, p. 576 (U.S. Government Printing Office 1894).Silver, David. Lincoln's Supreme Court, p. 29 (University of Illinois Press, 1956). On that same day, the executive branch – namely, a U.S. Marshal – attempted to execute Taney's writ of attachment, but the marshal was refused entry into the fort. There is no concrete documentation that Cadwalader had received those instructions prior to the Marshal's being refused entry at Fort McHenry. Because the Marshal was unable to serve the attachment, the citation for contempt was never adjudicated. At the end of the Merryman litigation, it became a nullity, as do all civil contempt orders at the termination of litigation.

Decision On May 28, Taney stated from the bench that the President can neither suspend habeas corpus nor authorize a military officer to do it, and that military officers cannot arrest a person not subject to the rules and articles of war, except as ordered by the courts. Taney noted that, while the marshal had the right to call up the posse comitatus to assist him in seizing General Cadwalader and in bringing him before the court, it was probably unwise for the marshal to do so, as the civilian and military authorities might collide and violence ensue, and thus Taney would not punish the marshal for failing in his task. He then promised a more lengthy, written ruling within the week and ordered that it be sent to President Lincoln, "in order that he might perform his constitutional duty, to enforce the laws, by securing obedience to the process of the United States".