The U.S. National Archives and Records Administration describes USCAR's history thus:[3] Following signing of the Instrument of Surrender, 2 September 1945, Ryukyu Islands were administered by Department of the Navy, 21 September 1945 – 30 June 1946, with Commanding Officer, Naval Operating Base, Okinawa functioning as chief military government officer under authority of Commander-in-Chief U.S. Pacific Fleet.

When the Treaty of San Francisco came into force in April 1952, the Ryukyu Islands were placed under U.S. administration temporarily.

After a formal agreement reached on 17 June 1971, control of Okinawa was given back to Japan on 15 May 1972,[9] and USCAR was abolished.

The post of Governor (民政長官, Minsei Chōkan) was created in 1950 and replaced in 1957 by the High Commissioner of the Ryukyu Islands (琉球列島高等弁務官, Ryūkyū-rettō Kōtō-benmukan) until 1972.

The ensign changed to "Hinomaru below a triangular flag labeled "Ryukyus" and "琉球" (Japanese for "Ryukyu") in 1967.

[11][12] Media related to United States Civil Administration of the Ryukyu Islands at Wikimedia Commons