1. June 12, 1898 marked the day that Hawaii was officially annexed by the United States, becoming the 50th state in the nation. This event marked the end of Hawaii's monarchy, as the Hawaiian Kingdom was dissolved and the islands were taken over by the US government.

2. In 1942, on June 12, Kamehameha Day was officially recognized as a state holiday in Hawaii. This day honors the legendary Hawaiian king, Kamehameha I, who united the Hawaiian islands under his rule in the late 18th and early 19th centuries.

3. On June 12, 1971, the USS Hawaii (SSN-776) submarine was launched, becoming the first ship to be named after the state of Hawaii. The USS Hawaii is an attack submarine that is still in service today, and has been deployed to various locations around the world.

4. In 1998, on June 12, a state constitutional amendment was passed in Hawaii that granted the right of marriage to all couples, regardless of their gender. This made Hawaii the first state in the US to legally recognize same-sex marriages.

5. June 12 is also significant in Hawaiian culture as it marks the start of Makahiki season, a traditional Hawaiian holiday that celebrates the harvest and honors the god Lono. This season lasts for four months and is marked by various festivities, including sports competitions, cultural events, and feasts.