@buckhorncliffs: Understanding Martial Law and How to Prepare Martial law involves direct military control over civilians, declared by the President or a state governor in response to severe emergencies like natural disasters, civil unrest, insurrection, or foreign invasion. Historical instances include President Lincoln's era, post-Pearl Harbor, and 1957's school desegregation enforcement. Under martial law, expect restrictions on movement, potential unlawful detention, and loss of civil liberties.