The Hawaiian Islands were discovered in 1778 by Captain James Cook. The native Hawaiians were Polynesians and worshipped tiki gods. In the decades after Cook's visit the islands were united under one chief after the great war chiefs wars of unity.
Hawaii became united under King Kamehameha who forced all independent kingdoms in the Hawaiian Islands to join a Hawaiian Kingdom under his rule. He did not do this via diplomacy or by elections. He did it by conquest in the warrior traditions of the ancient hawaiians, but with the help of European weapons.
Hawaii also was the site of the attack on Pearl Harbor the infamous sneak attack by the Japanese Navy.