Martial law and the Supreme Court

DESCRIPTION: Extension of military rule to civilian populations during times of war and other emergencies.

SIGNIFICANCE: Martial law allows the military to carry out wartime and other military operations with limited oversight under the US Constitution. The Supreme Court has upheld the legality of martial law in certain circumstances and has established limits to prevent abuse of this authority.

Under martial law, military officials have the authority to take actions that suspend some or all civil liberties that would otherwise be considered unconstitutional. Justification for martial law lies in the fundamental concept of self-defense. When survival is threatened, people’s first obligation must be to self-preservation, not the Constitution. Although no specific provision in the Constitution authorizes martial law, the Supreme Court has found that the concept is an implicit part of the constitutional order. Some evidence for this position comes from Article I, Section 9, which provides for the suspension of the writ of habeas corpus in limited circumstances. Partially because martial law is not plainly set forth in the Constitution, there is uncertainty about what the term means, about what actions may be taken during martial law, and about whether such actions are entrusted to Congress or the president.

The Court has occasionally considered the constitutionality of martial law. During the Civil War (1861-1865), President Abraham Lincoln declared martial law several times. Shortly after the Civil War began in April 1861, President Lincoln authorized military commanders to suspend the writ of habeas corpus along key transportation routes between Philadelphia and Washington, D.C., in response to pro-Confederate unrest. In 1862, he expanded this action by issuing a broader proclamation that suspended habeas corpus nationwide for individuals suspected of disloyalty or interfering with the Union war effort. Throughout the war, military tribunals were used to try civilians in areas under martial law, particularly where civil courts were closed or deemed ineffective.

Chief Justice Roger Brooke Taney, sitting as a circuit judge in Baltimore, Maryland, was subsequently presented with a claim by John Merryman that he was being held illegally by President Lincoln’s army. In Ex parte Merryman (1861), Taney concluded that President Lincoln’s suspension of the writ was illegal. President Lincoln never formally responded to the charge, but he continued to issue orders suspending the writ. In Ex parte Vallandigham (1864), however, the Supreme Court did not review Clement Vallandigham’s military conviction. It denied his petition for certiorari, concluding that it lacked jurisdiction to revise the proceedings of a military commission, thus leaving Vallandigham’s conviction undisturbed.

After the end of the Civil War, the Court was presented with another opportunity to consider the constitutionality of martial law. In Ex parte Milligan (1866), the Court held that suspension of the writ of habeas corpus did not authorize the military trial of civilian Lambdin P. Milligan in Indiana while the civilian courts were open and functioning. Writing for the Court, Justice David Davis concluded that the Constitution is a law “for rulers…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.” Nevertheless, Davis concluded that the Constitution permitted martial law when war prevailed, and closure of the civilian courts made it impossible to administer justice.

The Court also considered the constitutionality of martial law during World War II. In 1941, immediately after the attack on Pearl Harbor, the governor of Hawaii declared martial law, an action ratified by President Franklin D. Roosevelt two days later. In Duncan v. Kahanamoku (1946), the Court considered a challenge to that order by two civilians who had been convicted by military courts even though the civilian courts were open. In his opinion for the Court, Justice Hugo L. Black wrote that “our system of government clearly is the antithesis of total military rule.” Citing Milligan, Black concluded that the convictions should be overturned because the conditions specified in Milligan had not been satisfied. Duncan, like Milligan, speaks of the permissibility of martial law and its limits. In both cases, however, the Court issued opinions only after hostilities were over.

Between World War II and the twenty-first century, there were no major Supreme Court cases that explicitly addressed or upheld martial law in the traditional sense. However, the Court occasionally touched on related issues involving national security, emergency powers, or the limits of military authority, though these did not rise to the level of full martial law.

One such case was Laird v. Tatum (1972), which involved the US Army’s surveillance of civilian political activity during the Vietnam War era. The plaintiffs contended that the monitoring program, intended to gather information on protests and civil unrest, had a chilling effect on First Amendment rights and obscured the boundary between military and civilian authority. The Supreme Court dismissed the case for lack of standing, ruling that the plaintiffs had not demonstrated a specific injury. While the Court did not rule on the constitutionality of domestic military surveillance, the case raised important concerns about the military’s expanding presence in civilian life. This decision reflected a broader judicial reluctance to define or restrict the boundaries of martial law, as emergency powers during this period were typically exercised through legislation or executive action rather than formal declarations.

According to a 2020 publication by the Brennan Center for Justice, the Supreme Court’s rulings on martial law at the federal level are limited and complicated. State officials do have the power to declare martial law, but their actions must abide by the US Constitution and are subject to review in federal court.

Bibliography

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Corwin, Edward S. Total War and the Constitution. Alfred A. Knopf, 1947.

Epstein, Lee J., et al. Constitutional Law for a Changing America: Rights, Liberties, and Justice. 12th ed., CQ Press, 2024.

“Ex parte Vallandigham.” Legal Information Institute, www.law.cornell.edu/supremecourt/text/68/243. Accessed 6 Apr. 2026.

Fairman, Charles. The Law of Martial Rule. 2nd ed., U of Chicago P, 1940.

Merriam, Eric. “Necessary Necessity: Courts’ Historical Assessment of the Conditional Precedent for Martial Law.” University of Oklahoma College of Law, 2023, digitalcommons.law.ou.edu/cgi/viewcontent.cgi?article=2259&context=olr. Accessed 6 Apr. 2026.

Neeley, Mark E. The Fate of Liberty: Abraham Lincoln and Civil Liberties. Barnes & Noble, 2007.

Nunn, Joseph. “Martial Law in the United States: Its Meaning, Its History, and Why the President Can’t Declare it.” Brennan Center for Justice, 20 Aug. 2020, www.brennancenter.org/our-work/research-reports/martial-law-united-states-its-meaning-its-history-and-why-president-cant. Accessed 6 Apr. 2026.

Rankin, Robert. When Civil Law Fails. Duke UP, 1939.

Rossiter, Clinton, and William J. Quirk. Constitutional Dictatorship: Crisis Government in the Modern Democracies. Routledge, 2017.