Hawaii under Martial Law
Immediately after the attack on Pearl Harbor, Hawaii was deemed a war zone, meaning it was a potential target of invasion and a possible refuge for enemy agents. On the day of the attack, the territorial governor suspended the writ of habeas corpus — the constitutional protection against being imprisoned or detained without judicial approval — and signed a declaration of martial law prepared by the army. General Short, the army commander on Oahu, declared himself military governor. He was relieved of command December 17, but martial law — the most severe since the Civil War — continued until October 24, 1944.
Martial law during wartime was allowed in Hawaii under the same act of Congress that had made the island chain a U.S. territory. As a result of the declaration, the military ordered a strictly enforced nighttime blackout. Anyone caught with a lit cigarette, pipe, or cigar during the blackout was subject to arrest, as was anyone else if the light of their radio dial or kitchen stove burner could be seen through the house windows. The army also instituted a 6:00
In 1946, the U.S. Supreme Court, after hearing appeals from Hawaiian residents arrested during the war, declared that the writ of habeas corpus should not have been suspended and that declaration of martial law did not automatically allow the military to take over civilian courts, even during wartime.
Fearful of another enemy attack at any time, officials confiscated more than 300,000 acres of land for military use and enacted severe censorship. All outgoing mail was read by military censors, and letters that could not be edited with black ink or scissors were returned to the sender to be rewritten. Long-distance telephone calls were required to be in English so that military personnel could listen in.
Fearing that Japanese invaders might try to disrupt U.S. currency, the military ordered all Hawaiians to turn in all U.S. paper money, which was burned and replaced with bills with HAWAII overprinted on them. In addition, Hawaiians were forbidden to make bank withdrawals of more than $200 in cash per month or to carry more than $200 in cash. To keep track of civilians, the military issued identification cards to everyone over the age of six; anyone caught without a card was subject to arrest.
The military also oversaw the Hawaiian legal system, with military courts trying thousands of cases, most of them having nothing to do with wartime security. People accused of a crime went before a military judge who heard the charges — typically without the presence of a lawyer — and then passed sentence, which could be revoked only by a pardon from the military governor.
Many people fought the sustained martial law. In 1944, a federal judge ruled that military governing of Hawaii was no longer valid, but the military ignored the ruling and President Roosevelt had to step in. In October 1944, he announced the suspension of martial law and the restoration of habeas corpus.

