1. Hawaiian Kingdom Established - On March 12, 1860, Kamehameha IV declared the formal establishment of the Hawaiian Kingdom in a speech given in front of the legislature. Kamehameha IV was the fourth monarch of the Hawaiian Kingdom, reigning from 1855 to 1863, and oversaw many significant changes in the kingdom during his short reign.

2. Pearl Harbor Attack - On March 12, 1942, just three months after the attack on Pearl Harbor, the first American counterattack against Japan took place on the Marshall Islands. This attack signaled the start of the Pacific War and was a significant event in US military history.

3. Queen Liliuokalani's Arrest - On March 12, 1895, Queen Liliuokalani was arrested and imprisoned by the Republic of Hawaii. The queen had been working toward the restoration of the Hawaiian monarchy, which had been overthrown in 1893, and her arrest was a major setback for these efforts.

4. Hilo Earthquake - On March 12, 1975, a magnitude 7.2 earthquake hit the island of Hawaii, causing significant damage in the town of Hilo. The earthquake caused landslides, tsunamis, and widespread power outages, but fortunately, there were no fatalities.

5. Honolulu Marathon - Since the late 1970s, March 12 has been the date of the annual Honolulu Marathon, one of the largest marathons in the world. The 26.2-mile race starts in downtown Honolulu and finishes in Kapiolani Park, attracting thousands of participants from across the globe.