High Quality Content by WIKIPEDIA articles! An insular area is a United States territory, that is neither a part of one of the fifty U.S. states nor the District of Columbia, the federal district of the United States. They are called "insular" from the Latin word insula ("island") because they were once administered by the War Department`s Bureau of Insular Affairs, now the Office of Insular Affairs at the Interior Department. The term insular possession is also sometimes used.