Hawaii was never "discovered as a state"—statehood is a political act, not a geographic discovery. The timeline:
Captain James Cook (HMS Resolution) made the first documented European contact with the Hawaiian Islands on January 18, 1778, landing at Waimea, Kauai. He named them the "Sandwich Islands" after his patron, the Earl of Sandwich. Cook was killed at Kealakekua Bay in 1779.
Polynesians discovered and settled Hawaii ~1000–1200 AD, navigating 2,500+ miles from the Marquesas/Tahiti using stars, currents, bird flight. They developed a sophisticated society—ahupua'a land system, aquaculture, monumental architecture—centuries before European arrival.
After a U.S.-backed overthrow of Queen Liliʻuokalani (1893), the Republic of Hawaii was annexed by the Newlands Resolution (July 7, 1898) — a congressional joint resolution, not a treaty.
On August 21, 1959, President Eisenhower signed the Hawaii Admission Act. Hawaii became the 50th state after a referendum with 94% approval (on 35% turnout; many Native Hawaiians boycotted).