Guam is thought to have been inhabited by people since about 1500 BC, when it was discovered by Austronesians, the distant ancestors of the local Chamorro people. Owing to a lack of written records, not much is known about the early Chamorro society, but the latte stones — a type of structure dating from that period — dot the island (and others in the Marianas). It's not certain how a Neolithic people with no knowledge of metals ever cut these stones, but they were most likely used as supports for the houses of the privileged class. Similarities between the latte stones and some wooden structures in the Philippines and Indonesia have been pointed out, and more imaginative minds might even see resemblances with the moai of Easter Island far to the east.
The first European contact came in 1521, with the Portuguese explorer Ferdinand Magellan on his famed circumnavigation of the world, sponsored by Spain. Having no counterpart of the western concept of "ownership" in their culture, curious Chamorro canoed out to Magellan's ship, relieving it of whatever they could get their hands on. As a result, Magellan named the islands Islas de los Ladrones, "islands of the thieves."
Spain claimed the island in 1565 and Christianity arrived soon after. Guam became one of the most favorable harbors in the trans-Pacific maritime routes, serving as a common port-of-call for the ocean-going galleons between Mexico and the Philippines, both major possessions of the global Spanish Empire then. It was around this time that the modern Chamorro culture started to take shape, when intermarriages between the locals, Filipinos, and the Spaniards were common.
Guam was ceded to the U.S. by Spain in 1898 after the Spanish-American War. Captured by Japan and its army in 1941, it was retaken by the U.S. after an occupation lasting three years, during which locals were often treated brutally as defeated enemies.
In 1950, Guam was elevated to the status of an organized territory, and all locals were granted American citizenship. In the 1960s, there was even briefly a discussion of forging all American possessions out in the Western Pacific (which included Guam, the Northern Mariana Islands, as well as now-independent Palau, Micronesia, and Marshall Islands) into a full-fledged U.S. state centered in Guam, the largest and most populous island of all between Japan, New Zealand, the Philippines, and Hawaii. However, this proposal was quickly dismissed by Guamanians, mainly due to their mistrust of their Chamorro brethren on the Northern Marianas, who loyally served the Japanese during the occupation of Guam. The Northern Marianas had been a Japanese possession between World War I and the end of World War II; hence, the Chamorro of Guam and the Chamorro of the Northern Marianas were on opposing sides.
As Guam is the westernmost point in the Pacific Ocean to fall within U.S. territory (so far west it is in the Eastern Hemisphere), the military installations on the island are some of the more strategically important U.S. bases in the Western Pacific.
During the 1980s and 1990s, Guam's tourism industry went through a massive boom fueled by the rapid growth of the Japanese economy and the strength of the Japanese yen. For Japanese tourists, Guam's Tumon Bay offered the convenience of a quick weekend island getaway: a lovely white sand beach and exotic American shopping and food only four hours by plane from Tokyo, with no jet lag (because their time zones are only one hour apart). In contrast, Honolulu was eight hours away and Los Angeles was ten hours away by plane, and both destinations necessarily meant severe jet lag and having to take an entire week off work. Many Western brands opened stores in Guam to cater to tourists from Japan and other East Asian countries, while continuing to operate in English and under the familiar framework of U.S. law.
Since the 2010s, Guam's tourism industry has begun to stagnate in the face of fierce competition from newer resort areas in East and Southeast Asia, the increasing tendency of many Western brands to open their own stores in Asia to directly serve Asian consumers, and the rise of e-commerce. The value of the Japanese yen collapsed against the U.S. dollar and, apart from occasional exceptions, has never really recovered. Attempts to compensate for the loss of Japanese tourists by soliciting tourists from South Korea and Taiwan have been only partially successful.
In 2012, the United States agreed with Japan that it would relocate American troops from Okinawa to Hawaii and Guam. The U.S. military buildup helped to sustain the island through the 2020s, but as a result, the island's economy is increasingly directly dependent upon U.S. federal military spending.
In the mid-2020s, there were still a significant number of luxury designer brands operating on Guam. In early 2026, luxury shopping operator DFS pulled out of Guam after 55 years, resulting in the departure of many of those brands.
