Samoa, chain of volcanic islands in the South Pacific, comprising the independent nation of Samoa (formerly Western Samoa), and E of long. 171° W, the islands of American Samoa, under U.S. control. The Samoan islands extend c.350 mi (560 km), with a total land area of c.1,200 sq mi (3,110 sq km), and lie midway between Honolulu, Hawaii, and Sydney, Australia. The major islands are volcanic and mountainous and are surrounded by coral reefs. Soil in the interior is rocky; most cultivation takes place along the coast. Temperatures range from 90°F (32.2°C) in December, the hottest month, to 75°F (23.9°C) in August; the annual rainfall is 190 in. (483 cm), with the rainy season occurring between December and March.
The natives are Polynesians who may have arrived in the islands as early as 1000 B.C. From Samoa they swept out across the Pacific (c.A.D. 1200), carrying Polynesian civilization to innumerable other islands. The Dutch explorer Jacob Roggeveen was the first European to visit (1722) Samoa. Subsequent European expansion into the islands led to disorder and violence, which was compounded by tribal warfare. The first European missionaries arrived in 1830. Between 1847 and 1861, the United States, Great Britain, and Germany sent representatives to Samoa, and in 1878 the United States and the Samoan kingdom signed a treaty giving the United States certain trade privileges and the right to establish a naval station at Pago Pago. Germany and Great Britain were accorded similar privileges in 1879. A tripartite treaty in 1899 between Great Britain, the United States, and Germany recognized U.S. interests east of long. 171°W; Germany was granted the western islands, and Great Britain withdrew from the area in consideration of rights in Tonga and the Solomon Islands. New Zealand seized the German islands in 1914 during World War I and received a mandate to administer them from the League of Nations in 1920. In 1946 they became a UN trust territory held by New Zealand. In 1962 the independent nation of Western Samoa was created from the New Zealand territory; it was renamed in 1997. The eastern islands remained under U.S. control. Since 2011, when Samoa moved to the west side of the international date line to align its days with Australia and New Zealand, the two Samoas have been on different sides of the date line.