Martial Law in the United States

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.

The term has no established definition in U.S. law, the Brennan Center notes. 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. The last two are harder to file. A National Guard general declared martial law in Tulsa during the 1921 race massacre, and the 1941 order in Hawaii came from more than one official.

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 the armed forces “to execute the laws” except where the Constitution or an act of Congress expressly allows it (18 U.S.C. 1385). Reading those two facts together, the Brennan Center concludes that under current law the president lacks any authority to declare martial law.

The closest the Supreme Court has come to the question is Youngstown Sheet & Tube Co. v. Sawyer (1952), when it struck down, 6-3, President Truman’s seizure of the steel mills during the Korean War. Justice Robert Jackson’s concurrence set the test courts still use: when a president acts against “the expressed or implied will of Congress, his power is at its lowest ebb” (Cornell LII). The Brennan Center argues that the Posse Comitatus Act puts a presidential declaration in exactly that weakest category.

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. He censored the press, enforced a curfew, detained civilians without charge, and kept military rule for more than two months after the battle; the federal district judge later held him in contempt and fined him $1,000 (Brennan Center). 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 martial law 29 times. Wars and invasions drew it twice.

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 1903 and 1904 over mine 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 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, the Court upheld the state’s declaration of martial law and wrote that the state itself must determine what degree of force a crisis demands. (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 the two civilians and held both entitled to be 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, the Court upheld the state’s declaration of martial law and wrote that the state itself must determine what degree of force a crisis demands.). 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 the two civilians and held both entitled to be 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. Chief Justice Taney wrote that “the State itself must determine what degree of force the crisis demands” (Cornell LII). The Brennan Center reads Luther as establishing martial law as an emergency power states can invoke.

1866, Ex parte Milligan. Lambdin Milligan was tried by a military commission in Indianapolis and sentenced to be hanged. Indiana’s civilian courts had never closed. The Court ruled for Milligan and wrote that “the Constitution of the United States is a law for rulers and people, equally in war and in peace” (opinion text, Wikisource). The laws and usages of war, it held, “can never be applied to citizens in states which have upheld the authority of the government, and where the courts are open.”

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 reached the Supreme Court, the justices held the military tribunals had no authority to try the two civilians and that both were “entitled to be released from custody” (Cornell LII). Martial law had already been lifted on October 24, 1944, more than a year before the ruling.

Four Different Powers People Confuse

Most arguments about martial law turn out to be 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.

The Insurrection Act’s limits are loose, though, and that worries lawyers in both parties. Jack Goldsmith, a Harvard law professor and a leader of the Presidential Reform Project, described the Act this way to NPR in March 2024.

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. Troops went into American cities anyway. From June 2025 the administration sent the National Guard or Marines into Los Angeles, Washington, Memphis, Portland, Chicago, and New Orleans, using weaker laws that stop well short of military rule. The deployments governors opposed ended in court; the ones they agreed to continued.

Federalized over a governor’s objection, and stopped in court. In Los Angeles, Chicago, and Portland, the administration put state Guard units under federal command through a call-up law, Section 12406, over the governors’ objections. On September 2, 2025, Judge Charles Breyer ruled that troops in Los Angeles broke the Posse Comitatus Act, the 1878 law that bars soldiers from civilian policing. A December 10, 2025 injunction ordered the remaining troops returned to the governor, and the Ninth Circuit let it take full effect on December 31 (Clearinghouse). In Trump v. Illinois on December 23, 2025, a 6-3 Supreme Court denied the government’s request to let the Chicago deployment proceed. It read “regular forces” in the call-up law as “likely” meaning the military, so the president likely needs a legal exception to the Posse Comitatus Act before calling up the Guard that way. All three cities’ federalized troops were gone by January 2026.

Deployed with a governor’s consent. Memphis and New Orleans used Title 32, which keeps the Guard under the governor while Washington pays. A Tennessee judge blocked the Memphis deployment on November 17, 2025. That ruling was reversed on standing on April 28, 2026, so the troops stayed. Louisiana’s Guard remained in New Orleans under an order extended through August 31, 2026; no later extension was found.

Washington, D.C., answers to the president. The District has no governor, so its Guard reports to the president. Trump sent troops in August 2025. Judge Jia Cobb found the deployment likely unlawful on November 20, 2025, and an appeals court put her ruling on hold on December 17. Nearly 5,000 troops were there in July 2026, and the mission has been extended through Inauguration Day 2029.

The border got a new legal theory. On August 14, 2026, a Justice Department legal opinion widened the power of active-duty troops to detain people for trespassing in military “national defense areas” along the southern border. A spokesperson told CBS the border task force has about 8,000 service members.

Minneapolis, January 15, 2026. Trump posted that he would “institute the INSURRECTION ACT” if Minnesota officials did not stop protests around immigration enforcement. Homeland Security Secretary Kristi Noem told reporters outside the White House that she had discussed the option with the president (NBC News). No proclamation followed, and invoking the Act requires one.

Where the Domestic Deployment Fights Stand

As of October 6, 2026

• Los Angeles Posse Comitatus ruling In litigation, violation found

  Judge Breyer found a violation on September 2, 2025. A December 10, 2025 injunction ordered the remaining troops returned to the governor, and the Ninth Circuit let it take full effect on December 31, 2025. (source)

• Chicago call-up (Trump v. Illinois) Blocked by a court, Supreme Court, 6-3

  The Court kept the deployment blocked on December 23, 2025. Troops withdrew in January 2026. (source)

• Portland call-up Blocked by a court, permanent injunction

  Judge Karin Immergut permanently blocked it on November 7, 2025. The Guard demobilized January 6, 2026.

• Washington, D.C., Guard mission In litigation, ruling stayed

  Found likely unlawful November 20, 2025, then stayed on appeal December 17, 2025. Extended through Inauguration Day 2029 (NPR). (source)

• Memphis Guard mission Agency action, court block reversed

  A state judge blocked it November 17, 2025. The ruling was reversed on standing April 28, 2026, so it continues.

• Border arrest power Agency action, Justice Department opinion

  An August 14, 2026 opinion widened troops' power to detain people in the border defense areas. (source)

• Insurrection Act reform (S. 2070, H.R. 4076) Proposal, in committee

  S. 2070 has 24 cosponsors and H.R. 4076 has 43. Neither has had a committee vote. (source)

Source: Civil Rights Litigation Clearinghouse; Supreme Court; Courthouse News; NPR; CBS News; Congress.gov

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 reach for stop short of replacing civilian government. The Posse Comitatus Act explainer follows each deployment in more detail.

The Honest Disagreement

The live legal question is not whether a president can declare martial law, but whether these narrower deployments are lawful.

The case for the deployments rests on statute and executive authority. Section 12406 lets the president call up the National Guard when he is “unable with the regular forces to execute the laws,” and the government told the Supreme Court that attacks on federal immigration officers had “greatly impeded” enforcement. It also argued that protecting federal personnel and property is an inherent constitutional power and is not “executing the laws” under the Posse Comitatus Act (Trump v. Illinois).

The case against them rests on the Posse Comitatus Act. Judge Breyer found that troops in Los Angeles carried out the civilian law enforcement the 1878 law forbids without congressional authorization. In the Illinois case, the Supreme Court read “regular forces” as the military, so the call-up power applies only where the military could lawfully execute the laws, and it found the government had not identified a source of authority that would allow that in Illinois. Justice Kavanaugh agreed on narrower grounds; Justices Alito, Thomas and Gorsuch dissented.

Neither side in these cases has claimed a power to replace civilian courts or suspend the Constitution. The fight is over the legality of troop deployments, not over military rule.

How Other Countries Limit Martial Law

In South Korea, lawmakers voted to block the declaration the same night and the president lifted it within six hours; he was later removed from office and sentenced to life in prison. In the Philippines, martial law lasted more than eight years, from Proclamation No. 1081 in September 1972 to Proclamation No. 2045 in January 1981. Ukraine’s decree has been renewed every 30 to 90 days since February 2022.

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 24 cosponsors (H.R. 4076 has 43), would rewrite the Insurrection Act. The Senate bill requires the president to consult Congress “to the maximum extent practicable,” issue a proclamation and a written report, and end a deployment after 7 days unless Congress approves it. It states that nothing in the Act authorizes suspending the writ of habeas corpus, and it ends any deployment a court enjoins (bill text).

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. Our National Guard explainer shows who commands the troops in each duty status.

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.

Many declarations followed disasters, not unrest. 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.

The president’s lack of authority is a legal conclusion, not a ruling. The Brennan Center concludes the president lacks any authority to declare martial law, but the Supreme Court has never directly held whether the federal government has the power, and Luther v. Borden left the degree of force to the state.

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. The Brennan Center concludes that under current law the president lacks any authority to declare martial law.

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 after the Cambridge riot of 1963. It ran from June 14, 1963 to July 8, 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 Hawaii, the Supreme Court ruled against the military trials in 1946, after martial law there had already ended in 1944.

What rights can be suspended under martial law?

Under past declarations, military orders replaced local law, curfews and travel limits applied to civilians, and people were held without charge. The Constitution allows habeas corpus to be suspended only in rebellion or invasion, in Article I, the part that covers Congress. The Supreme Court held in 1866 and again in 1946 that military courts cannot try civilians while civilian courts are able to work.

Is the Insurrection Act the same thing as martial law?

No. The Insurrection Act lets the president deploy troops to assist civilian authorities with law enforcement. Martial law usually means the military takes the place of civilian government, and no federal statute authorizes the president to declare it, according to the Brennan Center. Even under martial law, the government cannot suspend constitutional rights.

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 consultation with Congress, and state that the Act does not authorize suspending habeas corpus.
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 says. Governors issued 52 of the 68 declarations, and state law is where that power lives.
4. Learn the powers that get used instead. The national emergency powers explainer covers the declared emergencies still in force, and the Rule of Law hub tracks the deployment litigation.