Martial law in the United States refers to times in
United States history in which a region, state, city, or the whole
United States was placed under the control of a military body. On a national level, both the
US President and the
US Congress have the power, within certain constraints, to impose
martial law since both can be in charge of the militia. In nearly every state, the governor has the power to impose martial law within the borders of the state. In the United States, martial law has been used in a limited number of circumstances, such as New Orleans during the
Battle of New Orleans; after major disasters, such as the
Great Chicago Fire of 1871, the
1906 San Francisco earthquake, or during riots, such as the
Omaha race riot of 1919 or the
1920 Lexington riots; local leaders declared martial law to protect themselves from mob violence, such as
Nauvoo, Illinois, during the
Illinois Mormon War, or
Utah during the
Utah War; or in response to chaos associated with protests and rioting, such as the
1934 West Coast waterfront strike, in Hawaii after
Japan's attack on Pearl Harbor, and during the
Civil Rights Movement in response to the
Cambridge riot of 1963