Enclave An island of area with one set of geographic codes within and completely surrounded by an area with a different set of geographic codes; usually refers to unincorporated area that is completely surrounded by an incorporated place.
Enumeration district (ED) A small geographic entity established by the Census Bureau as a basic unit for data collection and tabulation in a decennial or special census before 1990. (For the 1970 and 1980 censuses it was superseded by the BG as the lowest level for which the Census Bureau tabulated sample data in those areas that had block numbers assigned.) An ED usually consisted of the area to be assigned to an individual enumerator for canvassing. All area included in a single ED was in the same governmental unit(s) or statistical area(s). The ED was replaced by the address register area (ARA) for data collection purposes in the 1990 census; it also was totally replaced by the BG as the lowest level of geography for which the Census Bureau tabulated sample data. See also address register area, block group, ED number, sample data.
EP See election precinct.
ESR See economic subregion.
Exclave A discontiguous part of a geographic entity; also referred to as an outlier. Usually refers to a small portion of an incorporated place that is completely separate from the remainder of the place.
Extended city An incorporated place that contains large, sparsely settled area(s) within its legally defined boundaries; that is, one or more areas with a population density of less than 100 persons per square mile, each of which is at least 5 square miles in extent, which together constitute at least 25 percent of the place’s total land area or at least 25 square miles. These low-density areas are classified as rural; the remainder of the extended city is classified as urban. Before the 1990 census, the Census Bureau identified extended cities only within urbanized areas.
