Martial law–also called martial rule–is a type of jurisdiction in which military authority temporarily replaces civil authority. As stated in the 1998 case of Mudd v. Caldera, martial law authorizes the military to exercise the responsibilities of branches who are unable to function, such as the legislature, executive branch, or the courts. This is usually in response to war, natural disaster, or civil unrest, and is limited to such times of emergency; as such, at the conclusion of the instigating circumstance, martial law must end and the civil authority resumed. Martial law has been declared in several countries throughout history, recently in Ukraine and the Philippines
In the United States, martial law can be declared on a national level by the President or Congress, or within the borders of a particular state by that state’s governor. Martial law was first declared in New Orleans, Louisiana by then General Andrew Jackson during the War of 1812. Since then, it has been declared multiple times, notably by President Abraham Lincoln during the Civil War and by Governor Poindexter in Hawaii following the attacks on Pearl Harbor during World War II. According to E. W. Killam’s Martial Law in Times of Civil Disorder, martial law has been declared nine times since World War II, most often in response to resistance of desegregation decrees during the Civil Rights era.
Martial law differs from military law, as was clarified in the 1924 case of Bishop v. Vandercook. Military law–which involves the organization, government, and discipline of troops–applies only to those individuals who are in military service. While a citizen can be governed by martial law, they cannot be governed by military law. As such, military personnel under a time of martial law must still act in accordance with civil law. Further, citizens who have been wronged by the improper exercise of military power retain the right seek remedies for that harm.
[Last updated in June of 2020 by the Wex Definitions Team]