Series Information File for the 2015 Cartographic Boundary File,  Urban Area-State-County , 1:500,000

The 2015 cartographic boundary KMLs are simplified representations of selected geographic areas from the U.S. Census Bureau's Master
                                 Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). These boundary files are
                                 specifically designed for small-scale thematic mapping. When possible, generalization is performed with the intent to maintain the
                                 hierarchical relationships among geographies and to maintain the alignment of geographies within a file set for a given year.
                                 Geographic areas may not align with the same areas from another year. Some geographies are available as nation-based files while others
                                 are available only as state-based files.

                                 The records in this file allow users to map the parts of Urban Areas that overlap a particular county.

                                 After each decennial census, the Census Bureau delineates urban areas that represent densely developed territory, encompassing
                                 residential, commercial, and other nonresidential urban land uses.  In general, this territory consists of areas of high population
                                 density and urban land use resulting in a representation of the "urban footprint."  There are two types of urban areas: urbanized areas
                                 (UAs) that contain 50,000 or more people and urban clusters (UCs) that contain at least 2,500 people, but fewer than 50,000 people
                                 (except in the U.S. Virgin Islands and Guam which each contain urban clusters with populations greater than 50,000).  Each urban area
                                 is identified by a 5-character numeric census code that may contain leading zeroes.

                                 The primary legal divisions of most states are termed counties.  In Louisiana, these divisions are known as parishes.  In Alaska, which
                                 has no counties, the equivalent entities are the organized boroughs, city and boroughs, municipalities, and for the unorganized area,
                                 census areas.  The latter are delineated cooperatively for statistical purposes by the State of Alaska and the Census Bureau.  In four
                                 states (Maryland, Missouri, Nevada, and Virginia), there are one or more incorporated places that are independent of any county
                                 organization and thus constitute primary divisions of their states.  These incorporated places are known as independent cities and are
                                 treated as equivalent entities for purposes of data presentation.  The District of Columbia and Guam have no primary divisions, and
                                 each area is considered an equivalent entity for purposes of data presentation.  The Census Bureau treats the following entities as
                                 equivalents of counties for purposes of data presentation: Municipios in Puerto Rico, Districts and Islands in American Samoa,
                                 Municipalities in the Commonwealth of the Northern Mariana Islands, and Islands in the U.S. Virgin Islands.  The entire area of the
                                 United States, Puerto Rico, and the Island Areas is covered by counties or equivalent entities.  

                                 The boundaries for counties and equivalent entities are as of January 1, 2010.

Tags: 2015, boundaries, cartographic boundary, county, generalized, kml, state, state or equivalent entity, u.s., ua, uc, united states, urban area, urban cluster, urbanized area
Organization: U.S. Census Bureau, Department of Commerce