Guam is an unincorporated territory of the United States located in the western Pacific Ocean. The island sits at the southern end of the Mariana Islands chain, approximately 3,800 miles west of Hawaii and 1,500 miles south of Tokyo. Guam spans 210 square miles, making it the largest island in Micronesia. The island measures roughly 30 miles long and ranges from 4 to 12 miles wide. Mount Lamlam, rising 1,334 feet above sea level, stands as the highest point. The island divides geographically into a flat limestone plateau in the north and volcanic mountains in the south. The Philippine Sea borders the western coast while the Pacific Ocean proper lies to the east.
The Chamorro people inhabited Guam for at least 3,500 years before European contact. Portuguese explorer Ferdinand Magellan, sailing under Spanish commission, arrived at Guam on March 6, 1521, marking the first recorded European encounter with the Mariana Islands. Magellan named the archipelago "Islas de los Ladrones," or Islands of Thieves, after islanders took items from his ships. Spain claimed formal possession but did not establish a continuous colonial presence until 1668, when Jesuit missionary Father Diego Luis de San Vitores arrived with instructions to convert the indigenous population to Catholicism. San Vitores founded a mission and began baptizing Chamorros, a practice that met resistance from some chiefs who saw Christianity as a threat to traditional social structures.
The Spanish-Chamorro Wars erupted in 1670 after the warrior Mata'pang killed Father San Vitores on April 2, 1672, near Tumon Bay. The conflict escalated into a series of uprisings and military campaigns that continued until approximately 1695. Spain employed superior weaponry and tactics to suppress resistance, forcibly relocating the Chamorro population from outlying islands to Guam and consolidating survivors into controlled settlements. Historians estimate the Chamorro population declined from approximately 40,000 to 50,000 before contact to fewer than 5,000 by 1710, due to warfare, disease, forced relocation, and social disruption. Spain governed Guam for 230 years, imposing Catholicism, the Spanish language in administration, and social structures that blended European and indigenous elements. The capital, Hagåtña, originally called Agana, served as the administrative center throughout Spanish rule.
The United States acquired Guam from Spain following the Spanish-American War. The Treaty of Paris, signed December 10, 1898, transferred sovereignty to the United States while Spain retained the rest of the Mariana Islands until selling them to Germany in 1899. The U.S. Navy governed Guam as a naval station from 1899 to 1941, restricting access and maintaining the island primarily for military purposes. During this period, Chamorros lived under naval administration with limited civil rights and no U.S. citizenship. The Navy banned the Chamorro language in schools and promoted English as the primary medium of instruction.
Japanese forces invaded Guam on December 8, 1941, just hours after the attack on Pearl Harbor. Approximately 5,400 Japanese troops overwhelmed the small U.S. garrison of 153 Marines and 284 naval personnel within two days. Japan renamed the island "Omiya Jima" or Great Shrine Island and occupied it until 1944. The occupation imposed harsh conditions on the Chamorro population. Japanese authorities interned or executed American civilians, forced Chamorros into labor camps, and requisitioned food supplies, causing widespread hunger. Occupation forces killed approximately 1,000 Chamorros during the occupation, often in reprisal for suspected resistance activities. Some Chamorros were beheaded at sites including Faha, Tinta, and Inarajan for possessing American flags or providing assistance to hidden U.S. servicemen.
American forces launched the Battle of Guam on July 21, 1944, landing approximately 55,000 troops from the 3rd Marine Division, 1st Provisional Marine Brigade, and 77th Infantry Division. The battle continued until organized Japanese resistance ended on August 10, 1944, though Japanese holdouts remained in the jungle for years. American forces sustained 1,747 killed, 6,053 wounded, and 70 missing. Japanese forces lost approximately 18,500 killed and 1,250 captured. Sergeant Shoichi Yokoi, a Japanese soldier, hid in Talofofo until local hunters discovered him on January 24, 1972, making him one of the last known Japanese holdouts from World War II. July 21 remains Liberation Day, Guam's most significant public holiday, commemorating American recapture and the end of Japanese occupation.