structural:scholar_edition
Mariana Islands

The Mariana Islands are an arc-shaped archipelago made up by the summits of fifteen volcanic mountains. The island chain arises as a result of the western edge of the Pacific Plate moving westward and plunging downward below the Mariana plate, a region that is the most volcanically active convergent plate boundary on Earth. The Marianas were politically divided in 1898, when the United States acquired title to Guam under the Treaty of Paris, 1898, which ended the Spanish–American War. Spain then sold the remaining northerly islands to Germany in 1899. Germany lost all of her colonies at the end of World War I and the Northern Mariana Islands became a League of Nations Mandate, with Japan as the mandatory. After World War II, the islands were transferred into the United Nations Trust Territory System, with the United States as Trustee. In 1976, the Northern Mariana Islands and the United States entered into a covenant of political union under which commonwealth status was granted the Northern Mariana Islands and its residents received United States citizenship.