What Is Martial Law?

What Is Martial Law

Martial law is when the military takes over the jobs of civilian government. Military commanders issue orders directly to civilians, and military tribunals can replace civilian courts. Civil liberties that hold every ordinary day, including the writ of habeas corpus, free speech, and assembly, can be suspended or restricted.

It goes by other names. Older court rulings and state constitutions call it martial rule or military rule, and the terms mean the same thing. What separates military control from every other emergency power is the handoff. Civilian authority stops governing, and military authority takes its place.

Nothing in the U.S. Constitution grants anyone the power to declare it. There is no federal statute authorizing it either. The Supreme Court has never held that the president has this power. It has happened 68 times anyway, and almost all of it happened at the state level.

Who Can Declare Martial Law

This is the question most people get backward. Martial law is imagined as a presidential power, and in practice it has been overwhelmingly a state one.

The rest scatter across the map of American government. Federal military commanders declared it six times, acting on their own authority in the field. Territorial governors did it twice. Mayors did it twice, including the mayor of Chicago during the Great Chicago Fire in 1871. A state legislature did it once, and Congress did it once, when the 40th Congress placed the former Confederacy under military rule in 1867.

Governors can act because many state constitutions make the governor commander-in-chief of the state militia, and some state codes name the power outright. Washington’s statute, RCW 38.08.030, lets the governor proclaim a county or city “under either complete or limited martial law.” Other states have no express grant, and their governors have claimed the power as an implied part of executive power. There is no clean national rule, which is part of why the record is so uneven.

The president’s position is different, and weaker. No statute grants the power. The Posse Comitatus Act of 1878 makes it a crime to use federal troops for civilian law enforcement activities without express authorization from Congress. Legal scholars across the spectrum read those two facts together to mean a unilateral presidential declaration would not survive a court challenge.

The Constitution does address troops on American soil, but it points the other way. Article IV promises every state protection against invasion and against “domestic violence,” the founding-era phrase for insurrection or riot, when the state’s legislature or governor asks for help. That is a rescue a state requests, not a war power the president holds alone.

What Changes Under Military Rule

Every Declaration From 1814 to 1963

The Brennan Center published the full list of 68 declarations as a downloadable appendix, with a row for each one giving the date, place, cause, declaring official, and whether civilians ended up in military courts. Plotted on a single timeline, the shape of American martial law is not what the phrase suggests.

68 declarations, 1814 to 1963. One dot each, placed at the year it began.

• Labor dispute 29
• Other 15
• Riot or civil unrest 11
• Domestic war or insurrection 7
• Natural disaster 4
• War or invasion 2

Most declarations fall between 1877 and 1940, and 21 came in the 1930s alone. The record stops in 1963.

Source: Brennan Center for Justice, Guide to Declarations of Martial Law in the United States, appendix.

Martial law is not a modern threat that keeps recurring. It swelled with industrial labor conflict, peaked in the Depression, and stopped in 1963.

Year	Event	Category
1814	New Orleans, Louisiana	War or invasion
1842	Rhode Island	Domestic war or insurrection
1857	Utah Territory	Domestic war or insurrection
1861	Missouri	Domestic war or insurrection
1862	United States	Domestic war or insurrection
1864	Kentucky	Domestic war or insurrection
1866	New Orleans, Louisiana	Riot or civil unrest
1867	States of the former Confederacy, except Tennessee	Other
1870	Caswell and Alamance counties, North Carolina	Domestic war or insurrection
1871	Chicago, Illinois	Natural disaster
1877	Scranton, Pennsylvania	Labor dispute
1886	Seattle, Washington Territory	Riot or civil unrest
1889	Fort Bend County, Texas	Domestic war or insurrection
1892	Homestead, Pennsylvania	Labor dispute
1892	Shoshone County, Idaho	Labor dispute
1898	Pana, Illinois	Labor dispute
1899	Shoshone County, Idaho	Labor dispute
1900	Akron, Ohio	Riot or civil unrest
1900	Galveston, Texas	Natural disaster
1901	Jacksonville, Florida	Natural disaster
1902	Luzerne, Schuylkill, Carbon, Lackawanna, Susquehanna, Northumberland, and Columbia counties, Pennsylvania	Labor dispute
1903	Teller County, Colorado	Labor dispute
1904	Las Animas County, Colorado	Labor dispute
1904	San Miguel County, Colorado	Labor dispute
1904	San Miguel County, Colorado	Labor dispute
1912	Paint Creek and Cabin Creek, West Virginia	Labor dispute
1912	Paint Creek and Cabin Creek, West Virginia	Labor dispute
1913	Dayton, Ohio	Natural disaster
1913	Indianapolis, Indiana	Labor dispute
1913	Paint Creek and Cabin Creek, West Virginia	Labor dispute
1914	Butte, Montana	Labor dispute
1917	Houston, Texas	Riot or civil unrest
1919	Gary, Indiana	Labor dispute
1919	Longview, Texas	Riot or civil unrest
1920	Fayette County, Kentucky	Riot or civil unrest
1920	Galveston, Texas	Labor dispute
1920	Mingo County, West Virginia	Labor dispute
1921	Mingo County, West Virginia	Labor dispute
1921	Tulsa, Oklahoma	Riot or civil unrest
1922	Nebraska City, Nebraska	Labor dispute
1923	Oklahoma	Other
1924	Niles, Ohio	Riot or civil unrest
1930	Sherman, Texas	Riot or civil unrest
1931	A section of Oklahoma's border with Texas	Other
1931	Oklahoma oil fields	Other
1931	Several counties in Texas	Other
1932	Oklahoma oil fields	Other
1932	Oklahoma oil fields	Other
1933	In and around Highway Board of Georgia headquarters building	Other
1933	Oklahoma City, Oklahoma	Other
1933	Oklahoma oil fields	Other
1934	Area around the Grand River Dam in Arizona	Other
1934	Georgia	Labor dispute
1934	Minneapolis, Minnesota	Labor dispute
1934	Saylesville, Rhode Island	Labor dispute
1935	LaGrange, Georgia	Labor dispute
1935	Omaha, Nebraska	Labor dispute
1935	Vigo County, Indiana	Labor dispute
1936	Around the state capitol building in Oklahoma City, Oklahoma	Other
1937	Area around Narragansett Park in Pawtucket, Rhode Island	Other
1938	Newton, Iowa	Labor dispute
1938	Tulsa, Oklahoma	Labor dispute
1939	In and around Highway Board of Georgia headquarters building	Other
1940	Area around the Grand River Dam in Oklahoma	Other
1941	Hawaii Territory	War or invasion
1943	Beaumont, Texas	Riot or civil unrest
1959	Freeborn County, Minnesota	Labor dispute
1963	Cambridge, Maryland	Riot or civil unrest

The first came in 1814, when Gen. Andrew Jackson placed New Orleans under martial law during the War of 1812 and jailed the federal judge who tried to issue a writ of habeas corpus for a man his troops were holding. Twenty-one more came in the 1930s alone, as governors met strikes with troops during the Depression. Then the practice collapsed, with three declarations in the 1940s, one in the 1950s, one in the 1960s, and nothing after.

The causes make the pattern plain.

Labor disputes caused more declarations than war, insurrection, and natural disaster combined.

What Triggered Each of the 68 Declarations

Category	Value
Labor disputes (strikes, mine wars)	29
Other	15
Riots or civil unrest	11
Domestic war or insurrection	7
Natural disasters	4
War or invasion	2

Source: Brennan Center for Justice, Guide to Declarations of Martial Law in the United States, appendix.

Strikes drew troops 29 times. Wars and invasions drew them twice. The power Americans associate with foreign attack was used, over and over, on people who had stopped working.

The mine wars are the clearest case. West Virginia governors declared martial law over the Paint Creek and Cabin Creek coalfields three separate times between 1912 and 1913, and each time civilians were tried by military tribunal. Colorado governors declared it four times in three years over strikes in Teller, Las Animas, and San Miguel counties.

When Civilians Faced Military Courts

The appendix tracks something most coverage of martial law leaves out: whether civilians were actually tried by a military tribunal rather than a civilian court. That is the point where a declaration stops being a label and starts changing what happens to a person.

22%

31%

47%

• Civilians tried by military tribunal (22%) 15 declarations
• Record unclear (31%) 21 declarations
• No military trials of civilians (47%) 32 declarations

Source: Brennan Center for Justice, Guide to Declarations of Martial Law in the United States, appendix.

Eight of those 15 were labor disputes. Strikers in West Virginia, Montana, Texas, Georgia, and Nebraska were tried by officers rather than judges. The unclear third is worth its own mention: for 21 declarations the historical record is too thin to say what happened to the people detained, which is its own comment on how these episodes were documented.

What the Supreme Court Has Ruled

Three cases decide most of what is settled here, and they run in one direction. When martial rule reaches the Supreme Court, the Court keeps drawing the same line: if the civilian courts are open, the military does not get to replace them.

1. 1849 Luther v. Borden Growing out of the Dorr War in Rhode Island, this was the first time the Court upheld a declaration of martial law. It also held that deciding whether an emergency justified it was a political question, not one for judges. (source)
2. 1866 Ex parte Milligan A civilian sentenced to hang by a military commission in Indiana went free. The Court held that military tribunals cannot try civilians where the civilian courts are open and functioning, even during the Civil War. (source)
3. 1946 Duncan v. Kahanamoku After Pearl Harbor, Hawaii spent nearly three years under martial law with military tribunals in place of courts. The Court ruled 6-2 that those tribunals had no authority to try civilians, and ordered the prisoners released. (source)

Sources: Justia Supreme Court Center; Brennan Center for Justice.

The Supreme Court on Martial Law: 1849 — Luther v. Borden (Growing out of the Dorr War in Rhode Island, this was the first time the Court upheld a declaration of martial law. It also held that deciding whether an emergency justified it was a political question, not one for judges.). 1866 — Ex parte Milligan (A civilian sentenced to hang by a military commission in Indiana went free. The Court held that military tribunals cannot try civilians where the civilian courts are open and functioning, even during the Civil War.). 1946 — Duncan v. Kahanamoku (After Pearl Harbor, Hawaii spent nearly three years under martial law with military tribunals in place of courts. The Court ruled 6-2 that those tribunals had no authority to try civilians, and ordered the prisoners released.).

1849, Luther v. Borden. Rhode Island’s charter government declared martial law during the Dorr War, an armed fight over who the state’s legitimate government was. The Court let the declaration stand and said courts should not second-guess whether the emergency was real. That deference is the reason the power stayed available to governors for the next century.

1866, Ex parte Milligan. Lambdin Milligan was convicted by a military commission in Indiana and sentenced to death. Indiana’s civilian courts had never closed. The Court threw out the conviction and wrote that the Constitution does not go silent in wartime. This is the case that limits military jurisdiction over civilians, and it is the reason the writ of habeas corpus matters so much in this area.

1946, Duncan v. Kahanamoku. Hawaii’s territorial governor placed the islands under martial law hours after the attack on Pearl Harbor brought the United States into World War II, and the Army closed the civilian courts. The arrangement lasted two years, ten months, and 17 days. When it finally reached the Supreme Court, the justices applied Milligan and held the military tribunals had exceeded their authority. The ruling came after the fact, which is the recurring problem. Judicial review of martial law tends to arrive years after the detentions it condemns.

Four Different Powers People Confuse

Most arguments about martial law are really arguments about something else. Four separate legal regimes get collapsed into one phrase, and they differ in who can invoke them, what they authorize, and how often they are used.

The distinction that trips people up most is military law versus martial law. Military law is the Uniform Code of Military Justice, so it governs people who wear the uniform, it runs every day, and it never reaches civilians, who stay under civil law. Martial law is the opposite case, with military authority reaching outward onto people who never enlisted.

The Insurrection Act is the one that matters most right now, because it is a real statute a president can invoke alone, and because it stops well short of martial law. It lets troops assist civil authorities. It does not let the military govern, close courts, or suspend the Constitution.

Troops in Cities, No Martial Law Declared

No president has declared martial law in 2025 or 2026, and the Insurrection Act has not been invoked. The live fight is over a narrower tool, the domestic deployment of National Guard troops, and where it landed turned on whether the state’s governor agreed.

Federalized over a governor’s objection. In Los Angeles, Chicago, and Portland, the administration put state National Guard units under federal Title 10 command and used them for arrests, searches, and crowd control, over the governors’ objections. On September 2, 2025, Judge Charles Breyer ruled the Los Angeles deployment violated the Posse Comitatus Act, the 1878 law that bars troops from civilian policing. In Trump v. Illinois, a 6-3 Supreme Court on December 23, 2025 refused to lift the injunction blocking the Chicago deployment, after two lower courts held that political opposition is not rebellion. Control of California’s Guard returned to the governor in December 2025, and troops left all three cities by January 2026.

Deployed with the state’s cooperation. Where a governor agreed, the troops stayed. Memphis’s Republican governor accepted a Guard deployment that began September 29, 2025, and Louisiana’s Guard remained in New Orleans under a Title 32 order that keeps the governor in command while Washington pays. Neither state fought the deployment in court, so neither reached the Posse Comitatus question that sank Los Angeles.

Washington, D.C., is its own case. Trump sent roughly 2,200 Guard members to the capital in August 2025, and the force grew to about 2,800 by mid-2026, with a summer surge near 5,000. In November 2025, Judge Jia Cobb found the deployment unlawful, but a federal appeals court let it continue during the appeal, pointing to the District’s status as a federal district that Congress governs, where the Guard answers to the president rather than a governor. The mission has been repeatedly extended and remained in place past its one-year mark.

Minneapolis, January 15, 2026. Trump posted that he would “enact the INSURRECTION ACT” if Minnesota officials did not stop protests around ICE operations. Homeland Security Secretary Kristi Noem told NBC News she had discussed the option with the president that day. No proclamation followed, and invoking the Act requires one.

None of this was martial law. The military never replaced a mayor, closed a court, or tried a civilian. Every deployment ran on a Title 10 or Title 32 troop order, and the pattern from 200 years of history held. The powers a president can actually reach for stop short of replacing civilian government.

The Honest Disagreement

Serious lawyers disagree about how far a president can send troops into American cities. The question is not whether a president can declare martial law, which almost no one defends, but whether these narrower deployments are lawful. We lay out both cases and let you weigh them.

The case for the deployments rests on statute and precedent. Title 10, Section 12406 lets the president call up the National Guard when regular forces cannot execute the laws, and the administration argues that violence against federal immigration officers meets that bar. Courts have long been reluctant to second-guess a president’s judgment that an emergency exists, a deference running back to Luther v. Borden in 1849. On that reading, protecting federal personnel and buildings is a core executive job, not policing.

The case against them rests on the Posse Comitatus Act and the facts on the ground. Judge Breyer found that troops in Los Angeles were making arrests and running crowd control, the civilian law enforcement the 1878 law forbids without congressional authorization. Two courts in the Illinois case held that scattered protest is not the “rebellion” the call-up statute requires, and the Supreme Court let those rulings stand. On this reading, a president cannot turn a protest into a rebellion by calling it one.

Where the disagreement runs out is martial law itself. Even the administration’s lawyers have not claimed the power to replace civilian courts or suspend the Constitution. The fight is over the size and legality of a troop deployment, not over military rule, and that gap is the whole subject of this page.

How Other Countries Limit Martial Law

South Korea is the useful comparison because the check worked and it worked fast. The legislature voted the declaration down the same night, and the president who issued it went to prison. The Philippines shows the other outcome, where nothing stopped it for nine years. International law recognizes that governments may suspend some rights in a genuine emergency, but treaty standards require that the suspension be temporary, proportionate, and reviewable, which is exactly what a nine-year martial law regime is not.

Bills to Limit Emergency Military Powers

H.R. 4076, introduced by Rep. Chris Deluzio, and its Senate companion S. 2070, led by Sen. Richard Blumenthal with 21 cosponsors, would rewrite the Insurrection Act. The bills narrow the criteria for deployment, require the president to consult Congress, impose a seven-day limit without congressional approval, state plainly that the Act cannot be used to suspend habeas corpus or impose martial law, and open the decision to judicial review.

What Martial Law Is Not

The phrase gets used loosely, and the loose version makes it harder to recognize the real thing.

Troops in a city is not martial law. National Guard soldiers have deployed to American cities many times without any declaration. What defines martial law is the military displacing civilian government, not the presence of uniforms.

A state of emergency is not martial law. Emergency declarations are common, and dozens of federal ones are active right now. They unlock national emergency powers written into statute while courts, police, and elected officials keep doing their jobs.

Military law is not martial law. The Uniform Code of Military Justice governs service members. It has never applied to civilians.

Not every declaration was an atrocity. The mayor of Chicago declared it for 13 days after the Great Chicago Fire in 1871, and Galveston’s mayor did the same after the 1900 hurricane. Four of the 68 followed natural disasters. Treating every historical declaration as identical to the Philippines under Marcos flattens a record that genuinely varies.

The president’s lack of authority is a legal conclusion, not a guarantee. Scholars agree a unilateral presidential declaration would fail in court. The Supreme Court has never squarely ruled on it, and Luther v. Borden suggests courts may hesitate to second-guess an emergency call. The check is real but it is untested at the federal level.

Frequently asked questions

Can the president declare martial law? There is no statute granting that power and no constitutional provision creating it. The Posse Comitatus Act bars using federal troops for civilian law enforcement without express congressional authorization. Two presidents have declared martial law, both Lincoln, both during the Civil War. Legal scholars broadly agree a unilateral declaration today would be struck down.

Can a governor declare martial law? Yes, in many states, and governors have done it 52 times. The authority comes from state law rather than federal law. Some states name the power in a statute, like Washington’s RCW 38.08.030. Others treat it as implied in the governor’s role as commander-in-chief of the state militia.

Has martial law ever been used against strikes? Repeatedly. Labor disputes account for 29 of the 68 declarations, more than any other cause. In eight of those, civilians were tried by military tribunal rather than in a civilian court.

When was martial law last declared in the United States? In 1963, when Maryland Governor J. Millard Tawes declared it in Cambridge during civil rights protests. It ran from June 1963 to July 1964. No declaration has been recorded since.

Does martial law suspend the Constitution? Not by its own force. Ex parte Milligan held the Constitution applies in war and peace alike, and that military tribunals cannot try civilians while civilian courts are open. In practice, declarations have suspended rights anyway, and courts have often corrected it only years later.

Is the Insurrection Act the same thing? No. The Insurrection Act lets the president deploy troops to assist civil authorities while civilian government and the courts keep operating. It does not authorize military rule, military tribunals for civilians, or suspending the Constitution.

What You Can Do

1. Ask your senators to co-sponsor Insurrection Act reform. The Senate companion is S. 2070, which would add a seven-day limit, require congressional consultation, and state that the Act cannot be used to impose martial law.
2. Ask your representative to co-sponsor H.R. 4076, the House version of the same reform.
3. Ask your state legislators what your state’s martial law authority actually says. Governors issued 52 of the 68 declarations, and state law is where that power lives. Most states have never revisited these provisions.
4. Read the underlying record. The brief on 48 active national emergencies covers the powers that get used instead, and the Rule of Law hub tracks the deployment litigation.