The State of Hawaii is a state in the United States, located on an archipelago in the central Pacific Ocean southwest of the continental United States, southeast of Japan, and northeast of Australia. The state was admitted to the Union on August 21, 1959, making it the 50th state. Its capital is Honolulu on the island of Oahu. The most recent census puts the state's population at 1,283,388. This state encompasses nearly the entire volcanic Hawaiian Island chain, which is made up of hundreds of islands spread over 1,500 miles (2,400 km). At the southeastern end of the archipelago, the eight "main islands" are (from the northwest to southeast) Ni?ihau, Kaua?i, O?ahu, Moloka?i, Lana?i, Kaho?olawe, Maui, and Hawai?i. The last is by far the largest, and is often called the "Big Island" or "Big Isle" to avoid confusion with the state as a whole. This archipelago is physiographically and ethnologically part of the Polynesian subregion of Oceania.