World War II in Hawaiʻi: the December 7 attack, martial law and the Nisei soldiers

The December 7, 1941 attack on Pearl Harbor pulled the U.S. into World War II and put Hawaiʻi under martial law until October 1944, with military courts, curfews and blackouts. Hawaiʻi's Japanese American (Nisei) men formed the 100th Infantry Battalion and 442nd Regimental Combat Team, among the most decorated units for their size in U.S. history.

• Pearl Harbor: the surprise attack killed about 2,400 Americans; the USS Arizona Memorial and other sites are part of Pearl Harbor National Memorial (see places and holidays for visits and the Dec. 7 ceremony).
• Martial law: declared on December 7, 1941 and lifted in October 1944. In Duncan v. Kahanamoku (1946), the U.S. Supreme Court ruled that military trials of civilians in Hawaiʻi had been unlawful.
• Nisei soldiers: the 100th Battalion (mostly Hawaiʻi Nisei) and the 442nd ('Go for Broke') fought in Italy and France; Senator Daniel Inouye earned the Medal of Honor with the 442nd.
• Internment: about 2,000 people of Japanese ancestry from Hawaiʻi were detained, many at the Honouliuli camp in Central Oʻahu, now a National Historic Site.
• More to see: the Battleship Missouri, Pacific Aviation Museum and USS Bowfin at Pearl Harbor, and the U.S. Army Museum of Hawaiʻi in Waikīkī.

Sources: Wikipedia: Duncan v. Kahanamoku · U.S. Army: 442nd unit among the Army's most decorated · NPS: Honouliuli National Historic Site opens for tours

Last checked Nov. 1, 2026. Hours, fees and rules can change, so confirm with the official source before you go.