Hawaii is the newest of the 50 U.S. states, and is the only state made up entirely of islands. It is 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. Its capital is Honolulu on the island of Oʻahu. The most recent census estimate puts the state's population at 1,283,388.