Hawaii became part of the United States after a long period of  being an annexed territory. In 1897, the Hawaiian Territory was  established so that the United States could … protect the Hawaiians  from other influence. Hawaii became a state in 1959.Andrew Lubin.awaii became part of the United States after a long period of  being an annexed territory. In 1897, the Hawaiian Territory was  established so that the United States could … protect the Hawaiians  from other influence. Hawaii became a state in 1959. Andrew Lubin.