a territory of the United States, largest of the Mariana Islands in the Pacific Ocean. The United States acquired Guam from Spain as a result of the
Spanish-American War in 1898. Captured in 1941 during
World War II by the Japanese and recaptured by the Americans in 1944, Guam has served as an important U.S. naval base in the Pacific. In 1950 Guam officially became a U.S. territory and its people U.S. citizens.
