1. In 1846, King Kamehameha III declared June 15th as a public holiday to honor Kamehameha I, the first king of Hawaii. This holiday has since been celebrated as Kamehameha Day.

2. On June 15, 1909, Father Damien, a Belgian priest who devoted his life to serving and caring for patients with Hansen’s disease (leprosy) on the island of Molokai, was canonized by Pope Pius X. He became known as Hawaii’s patron saint.

3. In 1921, the U.S. Navy built a 20,000-seat stadium in Honolulu in honor of Admiral Thomas J. Halsey, who had recently passed away. The stadium was later renamed Aloha Stadium and became the home of the University of Hawaii’s football team and the NFL’s Pro Bowl.

4. On June 15, 1944, during World War II, U.S. troops launched an invasion of Saipan, a strategically important island in the Pacific. The battle lasted for several weeks and resulted in over 3,000 American casualties.

5. In 1978, the Mauna Loa Observatory on Hawaii’s Big Island recorded the highest levels of atmospheric carbon dioxide ever observed at that time. This milestone marked the beginning of scientists’ efforts to monitor and understand the effects of greenhouse gases on the Earth’s climate.