Hawaii became the 50th U.S. state on August 21, 1959.
Hawaii had been annexed by the United States in 1898 and organized as the Territory of Hawaii. Statehood supporters continued campaigning for admission during the twentieth century, while Congress debated the political and constitutional issues involved in adding the Pacific archipelago as a state.
President Dwight D. Eisenhower signed the Hawaii Admission Act on March 18, 1959. A referendum held in the territory produced overwhelming support for statehood, and Hawaii was admitted later that year. It became the second state added in 1959, following Alaska on January 3.
Hawaii remains the only U.S. state made up entirely of islands and the southernmost state in the country. Its admission completed the current 50-state Union. A frequent mix-up is the order of the 1959 admissions: Alaska was number 49, while Hawaii was number 50.