Following the Spanish–American War of 1898, Spain ceded Guam to the United States and sold the remainder of the Marianas (along with the Caroline and Marshall Islands) to Imperial Germany.
Japanese Acquisition
Early in World War I, Japan took the opportunity to declare war on Germany and invaded the Northern Marianas, hoping to annex them. In 1919, the League of Nations, precursor of the United Nations, awarded the islands to Japan by a mandate. During Japan's occupation, sugar cane became the main industry of the islands, and labor was imported from Japan and associated colonies (especially Okinawa and Korea). In the census of December 1939, the total population of the South Pacific Mandate was 129,104, of which 77,257 were Japanese (including ethnic Taiwanese and Koreans).
Hours after the Attack on Pearl Harbor, Japanese forces from the Marianas launched an invasion of Guam on December 8, 1941. Chamorros from the Northern Marianas, then under Japanese rule for more than two decades, were brought to Guam to assist the Japanese administration. This, combined with the harsh treatment of Guamanian Chamorros during the 31-month occupation, created a rift that would become the main reason Guamanians rejected the reunification referendum approved by the Northern Marianas in the 1960s.
American acquisition
Near the end of World War II, the United States military invaded the Mariana Islands on June 15, 1944, beginning with the Battle of Saipan, which ended on July 9 with the Japanese commander committing seppuku (a traditional Japanese form of ritual suicide). Of the 30,000 Japanese troops that defended Saipan, fewer than 1,000 remained alive at battle's end.[5] U.S. forces then recaptured Guam beginning July 21 and invaded Tinian (see Battle of Tinian) on July 24, which provided the take off point for the Enola Gay, the plane dropping the atomic bomb on Hiroshima a year later. Rota was left untouched (and isolated) until the Japanese surrender in August 1945, due to its military insignificance.
