The Battle of Hawai'i, also known as the Hawai'ian Campaign, was a ferocious four-month battle for control of the Hawai'ian Islands (also called the Sandwich Islands) in the central Pacific Ocean, fought between the Allied Powers and the Japanese from April to August 1926. The campaign featured some of the bloodiest fighting in the war, resulting in the deaths of as many as 500,000 American soldiers over the course of two months, 195,000 Colombian soldiers and upwards 900,000 Japanese soldiers, who often fought to the last man. The campaign ended with the successful victory at Kua'i on August 28th, 1926 and the defeat of the Japanese 7th Fleet five days later at the Battle of Honolulu Harbor, the first naval victory for the United States in the entire war.
The Battle of Hawai'i is often regarded as a turning point in the war - the Japanese had used the islands, which they had occupied since 1921, as the staging ground for their raids and, later, invasion during 1925, and the central position of Hawai'i in the Pacific allowed the Japanese to strike at even more distant enemies such as Colombia, Chile, and Oceania. By retaking Hawai'i, the Allies had reclaimed control of the ocean's most strategic islands and ended much of the naval advantage held by the Japanese over the eastern Pacific Ocean for the duration of the war.
The Battle of Hawai'i is considered one of the most significant military episodes in American history, and is immortalized in the 1962 film Oahu.