Habeas Corpus Is the Oldest Liberty in the Constitution, and War Tests It

Three Latin words, and they may be the most valuable in the history of freedom. Habeas corpus: "you shall have the body." Translated into plain English, they mean this: Jailer, bring the prisoner into court and tell the judge why you are holding him, and if you cannot show a lawful reason, let him go. That is it. No grand theory, no manifesto, no list of aspirations. A judge, a prisoner, a jailer and a question. Every tyranny in history has hated that question, because a tyranny's first tool is the power to lock someone up without having to answer it.

The privilege of the writ came from England into the original Constitution of 1787, before the Bill of Rights was written. It is the only common law writ the Constitution names. And every major American war has tested it, asking the same hard questions: when may the writ be suspended, and who has the power to suspend it? Here is the history, from a 1679 act of Parliament to a 2008 decision about Guantanamo Bay, and the answer the Constitution gives.

What the writ does

Define the term before telling the story. A writ is a court order. The writ of habeas corpus ad subjiciendum, to give it its full name, is an order directed to whoever holds a prisoner, requiring him to produce the prisoner before the court and state the cause of detention. The court then decides whether the cause is lawful.

Notice what the writ does not do. It does not decide guilt or innocence. It does not set the rules for trials. It asks one narrow question: is there legal authority to hold this person? If the jailer can point to a lawful warrant, a valid conviction, or a lawful charge awaiting trial, the prisoner stays. If the jailer can point to nothing but the command of a powerful man, the prisoner goes free. The writ turns every detention into a question of law rather than a question of power.

That is why it matters more than its modest procedure suggests. Rights on paper, speech, religion, jury trial, mean little if the government can simply imprison those who exercise them and refuse to explain. Habeas corpus is the enforcement mechanism behind many of the others.

The English inheritance

The idea is older than the writ. Magna Carta, sealed by King John in 1215, promised in its thirty-ninth chapter that no free man would be seized or imprisoned except by the lawful judgment of his peers or by the law of the land. Over the following centuries, the common law courts developed habeas corpus as the practical means of enforcing that promise.

The great test came under the Stuart kings. In 1627, in the Five Knights' Case, also called Darnel's Case, five gentlemen were imprisoned for refusing to pay a forced loan that Charles I had demanded without the consent of Parliament. They sought habeas corpus. The jailer's return said only that they were held by the special command of the king. The court refused to release them. If the king could imprison men by simply saying so, without stating a cause a court could examine, then the writ was empty.

Parliament answered with the Petition of Right in 1628, which declared that no free man should be imprisoned without cause shown. The struggle continued through civil war and restoration. Then, in 1679, under Charles II, Parliament passed the Habeas Corpus Act. It did not create the writ; it made it work. It required jailers to make prompt returns, fixed time limits, imposed heavy penalties on judges and officers who refused or delayed the writ, and forbade sending prisoners to places beyond the seas where the writ could not reach them. William Blackstone, the great English legal writer whose Commentaries the American founders studied, described the act as a second Magna Carta.

Note that last provision. The Stuarts had learned to evade the writ by moving prisoners out of the courts' reach. Parliament closed the loophole. Remember it when we get to Guantanamo.

Into the American Constitution

The colonists claimed the writ as part of their inheritance as Englishmen. When the delegates met in Philadelphia in 1787, nobody proposed to abolish it. The debate was over whether it could ever be suspended. Some delegates wanted no suspension at all. The Convention settled on Article I, Section 9, Clause 2:

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.

Read the conditions carefully. There must be a rebellion or an invasion. The public safety must require suspension. Both conditions must be met. Suspension is not available for ordinary crime waves, political unrest or administrative convenience.

Hamilton cited the clause in Federalist 84 as proof that the original Constitution already protected liberty, quoting Blackstone's warning that arbitrary imprisonment has been in all ages one of the favorite and most formidable instruments of tyranny; that argument is told in Hamilton Argued in Federalist 84 That a Bill of Rights Could Be Dangerous. The First Congress then gave the federal courts power to issue the writ in Section 14 of the Judiciary Act of 1789.

The whole clause is one of eight prohibitions on Congress in Section 9, discussed together in Article I, Section 9 Lists the Things Congress May Never Do to You. Its placement there is the first clue to the hardest question about it.

Who may suspend, the early answer

The text does not say who may suspend the writ. It is written in the passive voice: the privilege "shall not be suspended." But it sits in Article I, the legislative article, in a section that limits Congress.

The question first came up in 1807, during the Aaron Burr conspiracy. Two of Burr's alleged associates were arrested and sought release. Chief Justice John Marshall, in Ex parte Bollman, ordered them discharged and wrote that if at any time the public safety should require the suspension of the powers vested by the Judiciary Act in the federal courts, it is for the legislature to say so. Joseph Story, in his Commentaries of 1833, wrote that the power to suspend belonged exclusively to Congress. The early consensus was clear: suspension is a legislative act.

Then came a war that tested every consensus.

Lincoln, Merryman and the crisis of 1861

In April 1861, after the attack on Fort Sumter, Washington was in danger. Maryland, a slave state surrounding the capital on three sides, was divided. On April 19 a mob in Baltimore attacked Massachusetts troops marching to defend the capital. Rail bridges were burned. On April 27, 1861, President Lincoln authorized General Winfield Scott to suspend the writ along the military line between Philadelphia and Washington if resistance made it necessary. Congress was not in session.

On May 25, 1861, soldiers arrested John Merryman, a Maryland militia officer accused of helping destroy bridges, and held him at Fort McHenry. Chief Justice Roger Taney, sitting as a circuit judge, issued a writ of habeas corpus. The commanding officer declined to produce Merryman, citing the president's authorization. Taney then wrote an opinion, Ex parte Merryman, holding that the president had no power to suspend the writ, that the power belonged to Congress alone, and that the military had no authority to arrest a civilian not subject to military law. He sent the opinion to Lincoln. Merryman stayed in military custody for some weeks and was later turned over to civilian authorities and indicted; he was never tried.

Lincoln answered in his message to Congress on July 4, 1861. He argued that the Constitution did not say who could suspend the writ, that the provision was plainly made for a dangerous emergency, and that the framers could not have intended that the danger should run its course until Congress could be called together. Then he asked his famous question:

are all the laws, but one, to go unexecuted, and the government itself go to pieces, lest that one be violated?

Lincoln's attorney general, Edward Bates, issued an opinion supporting the president's power. Congress, for its part, did not settle the question until March 3, 1863, when it passed the Habeas Corpus Suspension Act authorizing the president to suspend the writ during the rebellion. Lincoln had already proclaimed a broader suspension on September 24, 1862, for those resisting the draft and engaged in disloyal practices. For how Lincoln's war powers were tested in the courts in another setting, see The Prize Cases of 1863 and How Lincoln Fought a War Before Congress Met.

Ex parte Milligan, the Constitution in war and peace

The war's most important habeas case came after the fighting stopped. Lambdin Milligan, an Indiana civilian, was arrested in October 1864, accused of conspiring with a secret society to aid the Confederacy, tried by a military commission in Indianapolis, and sentenced to death. He sought habeas corpus. The Supreme Court decided his case in April 1866 and released its opinions that December.

Justice David Davis wrote for the Court that the military commission had no jurisdiction to try a civilian in Indiana, a state where the federal courts were open and functioning and which was not a theater of active war. The Constitution, Davis wrote, does not bend to necessity:

The Constitution of the United States is a law for rulers and people, equally in war and in peace, and covers with the shield of its protection all classes of men, at all times, and under all circumstances.

He added that martial rule can never exist where the courts are open and in the proper and unobstructed exercise of their jurisdiction. Five justices held that not even Congress could have authorized such trials; four, led by Chief Justice Salmon Chase, would have said Congress could, but had not.

Milligan is the great American statement that war does not suspend the Constitution. Suspending the writ, even when lawful, only suspends the remedy. It does not authorize the government to try civilians in military courts where civil courts are open.

Later wars, later tests

The writ was suspended again during Reconstruction. Under the Enforcement Act of 1871, often called the Ku Klux Klan Act, President Ulysses S. Grant suspended it in nine South Carolina counties in October 1871 to break the Klan's campaign of terror against freed slaves and their white Republican allies. It was a lawful suspension, authorized by Congress, used against a genuine armed conspiracy.

After the attack on Pearl Harbor on December 7, 1941, the territorial governor of Hawaii suspended the writ and declared martial law, and military tribunals tried civilians for years afterward. In Duncan v. Kahanamoku (1946), the Supreme Court held that the territorial law authorizing martial law did not permit replacing the civilian courts with military tribunals for ordinary civilians. The ruling came after the war was over, which is often how these lessons arrive.

Guantanamo and Boumediene v. Bush

After the attacks of September 11, 2001, the government detained hundreds of captured fighters and suspects at the naval base at Guantanamo Bay, Cuba. The location was chosen in part because the government believed the federal courts' habeas jurisdiction did not reach it. Recall the 1679 act's ban on sending prisoners beyond the seas.

The Court responded in stages. In Rasul v. Bush (2004), it held that the federal habeas statute reached Guantanamo. In Hamdi v. Rumsfeld (2004), concerning an American citizen held as an enemy combatant, Justice Sandra Day O'Connor wrote for a plurality that a state of war is not a blank check for the president. Congress then passed the Detainee Treatment Act of 2005 and the Military Commissions Act of 2006, which withdrew federal court jurisdiction over habeas petitions from Guantanamo detainees and substituted a limited review in the D.C. Circuit.

In Boumediene v. Bush, decided June 12, 2008, the Court held five to four, in an opinion by Justice Anthony Kennedy, that the detainees had the constitutional privilege of habeas corpus, that Guantanamo, under complete and continuous American control, was not beyond the Constitution's reach, and that the substitute review was not adequate. Because Congress had not formally suspended the writ under the Suspension Clause's conditions, the Court held that the jurisdiction-stripping provision operated as an unconstitutional suspension. Chief Justice John Roberts and Justice Antonin Scalia wrote dissents. Scalia warned that the decision would make the war harder to fight and would almost certainly cost American lives, and argued that the writ had never extended to enemy aliens held abroad. The full case is told in Boumediene v. Bush and the Day Habeas Corpus Reached Guantanamo Bay.

The strongest objection, answered

Here is the best argument for executive suspension, the one Lincoln made, in its strongest form.

The Constitution is not a suicide pact. Invasions and rebellions happen suddenly, often when Congress is not in session, and the nation's survival may depend on swift action. The president is the commander in chief and takes an oath to preserve, protect and defend the Constitution; letting the Constitution itself be destroyed to protect one clause would betray that oath. The text names no branch. In 1861 Lincoln acted, Congress later ratified his course, and the Union survived. Any rule that would have stopped him is a rule that would have lost the war.

That argument deserves respect, because it comes from the most consequential president in our history at the gravest moment in it. It still fails, for four reasons.

1. The placement is the answer. The clause sits in Article I, among the limits on the legislature, not in Article II. Marshall in 1807 and Story in 1833 read it as a legislative power, before any partisan stake in the question existed.
2. Suspension is a lawmaking act. It removes a legal remedy from every person in a region. Removing a legal remedy is legislation. The president executes the law; he does not repeal its protections.
3. Lincoln's own conduct concedes the point. He took his case to Congress at its first session, asked for its approval, and later acted under an express statute. A president confident that the power was his alone would not have needed the Act of March 3, 1863.
4. The emergency exception has a narrow honest form. If the capital is under attack and Congress cannot meet, a president may act to preserve the government and then submit his action to Congress at once for approval or rejection. That is what Lincoln did in substance. It is a far cry from a standing executive power to suspend the writ whenever the executive judges the public safety requires it.

Boumediene presents a different question, and conservatives are honestly divided on it. The dissenters had serious history on their side about aliens held abroad, and serious concern about judges managing a war. But the core principle the majority defended, that the government cannot place prisoners beyond the reach of the writ simply by choosing where to hold them, is the principle of the 1679 act. The proper answer to the dissenters' concerns lay with Congress, which retained the power to suspend the writ formally if rebellion or invasion required it, and chose not to.

Why it matters

Habeas corpus is not a technicality for criminals. It is the line between a government of law and a government of men. Every person in the United States, citizen or not, is safer because a judge can demand that the government justify a detention. The day that question cannot be asked is the day every other right becomes a favor.

That is why war tests the writ, and why the answer matters so much. The founders gave the suspension power to the branch closest to the people, under narrow conditions, and the Supreme Court in Milligan told every future generation that the Constitution governs in war as in peace. The lesson of Korematsu, told in Korematsu Was Finally Repudiated in 2018, and Its Lesson Is About Deference, is the same lesson from the other side: when courts defer too much in wartime, liberty pays.

The case in brief

1. The writ of habeas corpus requires the government to justify every detention to a judge, and it came to us from Magna Carta, the Five Knights' Case of 1627 and the Habeas Corpus Act of 1679.
2. Article I, Section 9 forbids suspension except in rebellion or invasion when the public safety requires it, and its placement in the legislative article, read by Marshall in Ex parte Bollman (1807), gives the suspension power to Congress.
3. Lincoln suspended the writ in 1861, Taney objected in Ex parte Merryman, and Congress settled the matter with the Habeas Corpus Suspension Act of March 3, 1863.
4. Ex parte Milligan (1866) held that military commissions may not try civilians where civil courts are open, because the Constitution is a law for rulers and people equally in war and in peace.
5. Boumediene v. Bush (2008) held that the government cannot escape the writ by choice of location absent a formal suspension by Congress, a principle as old as the 1679 act.

What you can do: read Article I, Section 9, Clause 2 and the Milligan opinion's best-known paragraph, then ask your senators, through My Representatives, where they stand on detention without judicial review.