Definition - What does Martial Law mean?
Martial law is the type of law imposed when a country is at war, when there is a significant natural disaster, or during a similar emergency. It allows the military to take complete control of all the activities in the country.
As commander-in-chief, the U.S. president has the authority to declare martial law, which can only be in effect for a limited time.
Justipedia explains Martial Law
The sole purpose of martial law is to maintain law and order in times of crisis. But because it allows the military to take control over most, if not all, aspects of civilian life, the declaration of martial law has been linked to corruption, abuse of power and dictatorial practices in some countries.
In the United States, however, there are strict rules pertaining to the implementation of martial law. For instance, it cannot be imposed for an indefinite period, nor can it be imposed in any other way that unduly infringes on constitutional rights.