1. 1778: On April 16, 1778, British explorer Captain James Cook became the first European to visit the Hawaiian Islands. He arrived on Kauai and named the islands the "Sandwich Islands" in honor of the Fourth Earl of Sandwich.

2. 1862: The Mahele, a land division system that redistributed Hawaiian land during the mid-1800s, was implemented on April 16, 1862. This led to the privatization of land and the emergence of a Western-style land ownership system in Hawaii.

3. 1891: On April 16, 1891, the Wilcox rebellion took place on the island of Oahu. A group of Native Hawaiians and supporters of the overthrown Queen Liliuokalani attempted to overthrow the Republic of Hawaii, but were defeated by government troops.

4. 1946: The Hilo Massacre occurred on April 16, 1946, when police fired upon peaceful demonstrators protesting the high cost of living in Hawaii. In total, 21 people were killed and dozens were injured.

5. 1982: The Hawaii State Senate passed a resolution on April 16, 1982, recognizing Hawaiian language as the official language of Hawaii. This acknowledged the importance of preserving the Hawaiian language and culture in the state.