Try reading the Hawaiian history section on Encyclopedia Britannica.
The gobbling up @stanleybmanly mentioned occurred in 1887 – 1893, followed by annexation to US Territory status in 1900:
“King Kalakaua, who would be the last king of Hawaii, had lobbied for the Reciprocity Treaty. He lost the support of the planter class because of his attempts to revive Hawaiian culture and because of his profligate spending. In 1887 a company of “white” troops, the Honolulu Rifles, helped force upon him the Bayonet Constitution, which severely limited his powers and which allowed suffrage for the wealthy residents (who were generally American or European). When his successor, Queen Liliuokalani, seemed as if she would abrogate that constitution, the Committee of Safety, a group of American and European businessmen, some of whom were citizens of the kingdom, seized power in 1893, with the help of a company of U.S. Marines from the U.S.S. Boston, at anchor in the harbour. The U.S. government, under Pres. Grover Cleveland, refused to annex the territory, however, noting that the overthrow of the monarchy was an “act of war” accomplished against popular will using U.S. armed force (see primary source document: Controversy over Hawaii). A short-lived republic (an oligarchy of American and European businessmen) ensued, until the administration of Pres. William McKinley annexed the islands as U.S. territory in 1900.”