Hawaii became the 50th U.S. state in 1959.
President Dwight D. Eisenhower signed the Hawaii Admission Act, and Hawaii entered the Union on August 21, 1959. A statehood referendum held in Hawaii earlier that year produced overwhelming support for admission.
Hawaii is an archipelago in the central Pacific Ocean. Its islands were formed by volcanic activity, and the state includes Mauna Loa, one of Earth's largest active volcanoes by volume. Honolulu, on the island of Oahu, became the state capital.
Hawaii's admission followed Alaska's in January 1959. Because no state has joined since Hawaii, the United States has remained a 50-state union through the 2026 America250 anniversary.