, the largest and southernmost of the Mariana Islands, and a possession of the United States. It is in the Pacific Ocean, about 3,700 miles (5,950 km) west-southwest of Honolulu. Guam's area is 209 square miles (541 km2). The island is volcanic in origin and mountainous in the southern part. The climate is tropical and tempered by trade winds. Some of the islanders are engaged in the traditional occupations of farming or fishing, but Guam's economy is supported mainly by tourism and by U.S. military installations.
Native-born Guamanians are descended from Malays, Filipinos, Japanese, and Spaniards who mixed with the aboriginal Chamorros. Most Guamanians are Roman Catholics. English is the official language, but Chamorro is also widely spoken. The University of Guam is at Mangilao, near Hagåtña. Guam is under the jurisdiction of the U.S. Department of the Interior. Under the Organic Act of 1950, Guam has local self-government and Guamanians are United States citizens. The governor, the lieutenant governor, the legislature, and a delegate to the U.S. House of Representatives are elected.
Guam was originally settled by the Chamorros, a proto-Malayan people, between 3000 B.C. and 2000 B.C. Their descendants occupied the island at the time of European encounter by Ferdinand Magellan in 1521 A.D. Guam was colonized by the Spanish in 1668. In 1898, after the Spanish-American War, it was ceded to the United States. During World War II, Japan occupied the island. Following the granting of territorial status to Guam in 1950, it developed a thriving economy. Since then, islanders have voted several times in referenda to continue their status as a United States possession. The U.S. naval air station on the island was closed and converted to commercial use in 1995.
In 2000 the population, excluding military personnel, was 154,805; of Hagåtña, the capital, 1,100.