The Japanese attack on Pearl Harbor on December 7, 1941 lasted 110-minutes, from 7:55 am until 9:45 am. By 10:30 am, in co-operation with the Navy, the Army began to apply a tight censorship to prevent the transmission from Hawaiʻi of any unauthorized information about the attack or about the condition of Oʻahu’s defense forces after it was over.
Shortly after, Joseph Boyd Poindexter, Governor of the Territory of Hawaiʻi, by proclamation, invoked the powers granted him under the M-Day Act.
However, at 3:30 pm of the same day, Poindexter issued a second proclamation where he placed the Territory of Hawaiʻi under martial law and authorized the “Commanding General, Hawaiian Department, during the present emergency and until the danger of invasion is removed, to exercise all the powers normally exercised by me as Governor”. He followed-up with a telegram to the President of the US.
The Army’s Commanding General of the Hawaiian Department (Lt General Short) became the Military Governor of Hawai’i, assuming comprehensive executive, legislative and judicial powers.
The martial law regime affected every resident of the Territory of Hawaiʻi, citizen and foreign alike. Never before or after in American history were US citizens kept under martial law in such numbers or for so long a time.
Under martial law, military officers assumed all legislative, executive and judicial powers.
The two houses of the Hawaiʻi legislature, as well as judges of all courts, Territorial and federal, were not on the organizational chart as part of the martial law government. Under the martial law regime, there was no room for legislation, other than decrees by the military.
Japanese Americans were incarcerated in at least eight locations on Hawaiʻi. These sites that include Honouliuli Gulch, Sand Island, and the U.S. Immigration Station on Oahu, the Kilauea Military Camp on the Big Island, Haiku Camp and Wailuku County Jail on Maui, and the Kalaheo Stockade and Waialua County Jail on Kauaʻi.
In all, between 1,200 and 1,400 local Japanese were interned, along with about 1,000 family members. The number of Japanese in Hawai‘i who were detained was small relative to the total Japanese population here, less than 1%.
This was not the first proclamation of martial law in the Islands. On January 17, 1893, martial law was declared by the Provisional Government of the Hawaiian Islands.
Then, on January 7, 1895, Republic of Hawaiʻi President Sanford B Dole declared martial law following Kaua Kūloko (Civil War 1895) when forces attempted to return Queen Liliʻuokalani to the throne following the overthrow of constitutional monarchy. Martial law, then, lasted until March 18, 1895.