Hawaii became a state of the United States in 1959. It is the last state to join the Union. There were many reasons why both the United States would want Hawaii to become a state and there were many reasons why Hawaiians wanted Hawaii to become a state. Hawaii became a prime location for their Navy. It was out in the Pacific Ocean and could allow ships to dock quicker there than continue to transport themselves to the United States.
However, the U.S. and Hawaii had been connected long before it became a state. The people of Hawaii wanted to be part of making the laws and be represented in Congress. They petitioned to be admitted to the Union. It took some voting, but it finally happened.