Martial law has not been declared anywhere in the United States. As of 2026, no federal or state martial law declaration is in force, civilian courts are open, elected officials continue to govern, and constitutional rights remain enforceable through the ordinary legal system. The Insurrection Act, the closest federal statute people tend to associate with military rule, has not been invoked since 1992.
What About the 2025 National Guard Deployment
Recent military activity has driven much of the public concern, so it’s worth being precise about what happened. In June 2025, the White House issued a memorandum calling at least 2,000 National Guard members into federal service under 10 U.S.C. § 12406 to protect Immigration and Customs Enforcement personnel at locations where protests were occurring or anticipated.1The White House. Department of Defense Security for the Protection of Department of Homeland Security Functions The memorandum also authorized the Secretary of Defense to deploy additional regular armed forces, and it characterized certain protests as “a form of rebellion against the authority of the Government.”
None of that is martial law. The deployment did not replace civilian government with military authority, did not close civilian courts, and did not transfer executive, legislative, or judicial functions to military officers. Deploying troops to support a federal agency is legally and practically different from martial law, where the military itself takes over the functions of government.
What Martial Law Actually Means
Martial law refers specifically to the military replacing civilian government and exercising executive, legislative, and judicial power over the population of a given area.2Congress.gov. Constitution Annotated – ArtII.S2.C1.1.14 Martial Law Generally Soldiers enforce laws in place of police, military officers make policy decisions in place of elected officials, and military tribunals try cases in place of civilian courts. The military is in charge.
That total displacement of civilian authority is what separates martial law from other emergency measures. A governor can declare a state of emergency and activate the National Guard without imposing martial law. In that scenario, the governor still governs, police still enforce laws, courts still operate, and the Guard acts in a support role under civilian command. Most military deployments in American history have fallen into this category rather than genuine martial law.
Suspension of habeas corpus is a related but separate power. Suspending habeas corpus lets the government detain individuals without formal charges, but it doesn’t hand control of the government to the military. A martial law declaration can be accompanied by a habeas suspension, but the two have different constitutional roots and can exist independently.
Who Can Actually Declare Martial Law
The law here is murkier than most people expect. The Constitution never mentions martial law by name. No federal statute defines it or explicitly authorizes anyone to declare it. That silence has produced genuine disagreement about where the power resides at the federal level.
The President
Some legal scholars argue the president has inherent authority as Commander-in-Chief to declare martial law during extreme emergencies. Others contend the president can only act if Congress authorizes it first. The Supreme Court has addressed the limits of martial law but has never definitively settled whether the president can unilaterally impose it. What the Court has made clear is that only Congress can authorize military tribunals to replace civilian courts.2Congress.gov. Constitution Annotated – ArtII.S2.C1.1.14 Martial Law Generally That fact alone makes a unilateral presidential declaration of full martial law constitutionally suspect.
The president does have clear statutory authority under the Insurrection Act to deploy federal troops domestically. Invoking the Insurrection Act is not the same as declaring martial law. Civilian government stays in place, and constitutional rights remain enforceable.
State Governors
State officials have historically been on firmer legal ground when declaring martial law within their own borders. In Luther v. Borden, the Supreme Court ruled that a governor’s determination that insurrection exists is conclusive and not subject to judicial review at the moment of the declaration, provided the governor acts in good faith.2Congress.gov. Constitution Annotated – ArtII.S2.C1.1.14 Martial Law Generally Most state constitutions contain provisions allowing governors to mobilize military force during severe emergencies, and time limits on those emergency powers typically range from 30 to 90 days before the state legislature must weigh in.
State martial law declarations remain subject to federal constitutional limits. Actions taken under them must comply with the U.S. Constitution and are reviewable by federal courts.
Congress
Congress holds several constitutional powers that check martial law. It controls military funding, has the sole power to declare war, and can authorize or refuse to authorize military tribunals. Some scholars argue Congress is the only branch that can legally establish martial law in the full sense, since replacing civilian courts with military tribunals requires congressional action. Congress also holds the impeachment power as an ultimate check on any president who oversteps.
The Insurrection Act Is Not Martial Law
Because the Insurrection Act comes up in almost every public discussion of martial law, it’s useful to see what it actually does. The statute, codified at 10 U.S.C. §§ 251–255, gives the president three main pathways to deploy federal troops domestically: at the request of a state’s legislature or governor to suppress insurrection, when rebellion or obstruction makes it impracticable to enforce federal law through the courts, and, under § 253, to protect constitutional rights when state authorities are unable or unwilling to do so.3Office of the Law Revision Counsel. 10 USC Ch. 13 – Insurrection Before deploying troops under any of these provisions, the president must issue a proclamation ordering insurgents to disperse.4Office of the Law Revision Counsel. 10 USC 254 – Proclamation to Disperse
The Insurrection Act is the primary statutory exception to the Posse Comitatus Act, which generally makes it a federal crime to use federal armed forces to execute domestic laws.5Congress.gov. The Posse Comitatus Act and Related Matters Posse Comitatus applies only to federal forces. When a governor activates the National Guard under state authority, Guard members serve as state employees and the Act does not restrict their activities.
The Insurrection Act was last invoked in 1992, when President George H.W. Bush deployed federal troops during the Los Angeles civil unrest. Even a full invocation of the Act would not, by itself, constitute martial law.
The Legal Limits Courts Have Set
Even when martial law has been declared in American history, courts have never treated it as a blank check.
The Milligan Rule
The most important case is Ex parte Milligan (1866). Lambdin Milligan, a civilian in Indiana, was arrested by the military during the Civil War, tried before a military commission, and sentenced to death. The Supreme Court reversed his conviction, holding that military tribunals have no jurisdiction to try civilians where civilian courts are open and functioning.6Justia. Ex parte Milligan, 71 US 2 (1866)
That reasoning established the test that still governs today. Martial law can only arise where courts are actually closed, criminal justice cannot be administered according to law, and military operations are genuinely underway. The moment civilian courts can resume functioning, martial law must end. As the Court put it, continuing military rule after courts reopen is “a gross usurpation of power.”6Justia. Ex parte Milligan, 71 US 2 (1866) A spike in crime, political unrest, or widespread civil disobedience cannot justify martial law as long as judges can still hold court.
The Hawaii Precedent
The longest period of martial law in American history followed the attack on Pearl Harbor on December 7, 1941. The territorial governor declared martial law hours after the attack, and the Army’s commanding general became military governor, exercising sweeping executive, legislative, and judicial powers. Civilian courts were replaced by military tribunals that denied jury trials and habeas corpus rights. Martial law lasted nearly three years, ending on October 24, 1944.
In Duncan v. Kahanamoku (1946), the Supreme Court ruled that Congress had not authorized the military to replace civilian courts with tribunals under Hawaii’s Organic Act, even during wartime. The Court held that the term “martial law” in that statute was meant to allow vigorous military action for defense purposes, not to supplant the entire civilian legal system.7Legal Information Institute. Duncan v. Kahanamoku, 327 US 304 (1946)
The Constitution Doesn’t Switch Off
The Constitution permits suspending the writ of habeas corpus only during rebellion or invasion when public safety requires it.8Congress.gov. ArtI.S9.C2.1 Suspension Clause and Writ of Habeas Corpus That power has been exercised at the federal level only once, during the Civil War in 1863. Even when habeas corpus is suspended, the rest of the Constitution remains in force. Individuals detained under martial law can petition federal courts for release, and those courts can evaluate whether the underlying declaration was constitutional in the first place.
Has It Ever Happened Here
Yes, though rarely at the federal level. Martial law has been imposed at least 68 times throughout American history, the vast majority as state-level declarations. The reasons break down roughly as follows: labor disputes account for the largest share (around 29 instances), followed by riots or civil unrest (11), domestic insurrection (7), natural disasters (4), and war or foreign invasion (2).
Several episodes stand out. During the War of 1812, General Andrew Jackson imposed martial law in New Orleans to defend the city against British attack. During the Civil War, President Lincoln suspended habeas corpus and military authority was exercised extensively in border states. The 1906 San Francisco earthquake prompted a martial law declaration to prevent looting and maintain order in the devastated city. Labor conflicts in the early twentieth century, particularly in mining and waterfront industries, triggered numerous state-level declarations. Hawaii from 1941 to 1944 remains the most extensive American example, and the Duncan decision that followed narrowed the circumstances under which martial law could be imposed in future emergencies.
None of that history changes the current answer. As of 2026, no such declaration is in effect. The military deployments that have drawn public attention operate under statutes that leave civilian government, civilian courts, and constitutional rights intact.