High Quality Content by WIKIPEDIA articles! The Office of Insular Affairs (OIA) is a unit of the United States Department of the Interior that oversees federal administration of several United States possessions. It is the successor to the Bureau of Insular Affairs of the War Department, which administered certain territories from 1902 to 1939, and the Office of Territorial Affairs (formerly the Division of Territories and Island Possessions and then the Office of Territories) in the Interior Department, which was responsible for certain territories from the 1930s to the 1990s. The word "insular" comes from the Latin word insula ("island").