The early history of these islands paralleled that of Guam. Spanish and other explorers first visited the islands in the 16th century. Spain began colonizing the islands in 1668. Originally called Islas de Ladrones (Islands of Thieves), the Spanish renamed them in 1688 in honor of Queen Mariana of Spain. Spain sold the Marianas, as well as the Carolines and Marshalls, to Germany in 1899 to raise money after the Spanish–American War. In 1914, during World War I, Japan claimed jurisdiction over all these islands after entering the war on the side of the Allied Powers; it retained them officially under a 1919 mandate of the League of Nations. The United States gained control of the islands through military victories in 1944, and established a military government following World War II. On July 18, 1947, under a joint resolution of the U.S. Congress, President Harry Truman approved a trusteeship agreement between the United States and the Security Council of the United Nations, with the administrative authority resting with the Department of the Interior since June 29, 1951; however, because of their strategic significance, the Northern Mariana Islands remained under military control until 1961.
During the 30 years that followed, the U.S. Government provided the basis for the entities within the Trust Territory of the Pacific Islands (TTPI) to make a steady movement toward self-government. After extensive negotiations, the United States and the Northern Mariana Islands concluded a covenant on February 15, 1975, that would result in that entity becoming a commonwealth of the United States. In 1977, the U.S. Government announced its intention to terminate the trusteeship as soon as possible. Over several years, the governmental framework of the TTPI restructured itself into four separate entities, one of which corresponded to the Northern Mariana Islands; each adopted a new constitution, held elections, established its own government, and began to function autonomously, although within the framework of the trusteeship. The establishment of a separate government for the Northern Mariana Islands took place in January 1978 with the reorganization of the Mariana Islands District of the TTPI as the Commonwealth of the Northern Mariana Islands (CNMI). Final commonwealth status did not come until November 3, 1986, when President Ronald Reagan issued a proclamation that dissolved the trusteeship agreement for all of the TTPI except Palau.
