Guam (; Chamorro: Guåhån) is an organized, unincorporated territory of the United States located in the western Pacific Ocean. It is one of five U.S. territories with an established civilian government. Guam is listed as one of sixteen Non-Self-Governing Territories by the Special Committee on Decolonization of the United Nations. The island's capital is Hagåtña (formerly Agaña). Guam is the largest and southernmost of the Mariana Islands.
The Chamorros, Guam's indigenous people, first populated the island approximately 4,000 years ago. The island has a long history of European colonialism, beginning with its discovery by Ferdinand Magellan during a Spanish expedition on March 6, 1521. The first colony was established in 1668 by Spain with the arrival of settlers including Padre San Vitores, a Catholic missionary. For more than two centuries Guam was an important stopover for the Spanish Manila Galleons that crossed the Pacific annually. The island was controlled by Spain until 1898, when it was surrendered to the United States during the Spanish-American War and later formally ceded as part of the Treaty of Paris.
As the largest island in Micronesia and the only U.S.-held island in the region before WW II, Guam was captured by the Japanese on December 8, 1941, just hours after the bombing of Pearl Harbor, and was occupied for two and a half years.
During the occupation, the people of Guam were subjected to acts that included torture, beheadings and rape, and were forced to adopt the Japanese culture. Guam was subject to fierce fighting when U.S. troops recaptured the island on July 21, 1944, a date commemorated every year as Liberation Day.
Today, Guam's economy is supported by its principal industry, tourism, which is composed primarily of visitors from Japan. Guam's second largest source of income is the United States military.