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Relationship Files

These text files describe geographic relationships. There are two types of relationship files; those that show the relationship between the same type of geography over time (comparability) and those that show the relationship between two types of geography for the same time period.

 

Geographic Relationships Over Time (Comparability)

These files show the relationships (comparability) for the same type of geography over different periods of time (e.g. the relationship between places in 2010 and places in 2000).

Block Relationship Files

The 2010 Census Block Relationship files are provided as a tool to help data users compare the universe of Census 2000 blocks to the universe of 2010 Census blocks. From these files, data users may determine how 2000 blocks now relate to 2010 Census blocks and vice versa. Please use the links below to find out more information about the 2010 Census Block Relationship files and to download them.

County Subdivision Relationship File

The county subdivision relationship file provides a simple relationship between each 2010 Census county subdivision and its comparable Census 2000 county subdivision (if comparability exists) with an additional comments section to describe more detailed changes.  For the vast majority of records, there is a one-to-one relationship between a 2010 Census county subdivision and a Census 2000 county subdivision, although names and codes may have changed between censuses.  Where a 2010 Census record has no comparable Census 2000 county subdivision information, it is the result of new subdivisions being created from existing areas or the 2010 Census county subdivisions have changed so dramatically as to preclude any relationship.  The NOTES column provides additional information if required.

Relationships for governmental county subdivisions is based on continuing governmental status although there may have been substantial boundary changes or other changes that modified the boundaries.  For nonfunctioning legal county subdivisions and statistical entities, relationships are based on the entity still being defined for its "core" area.  In some states, most notably Louisiana, Maryland, and Mississippi, county governments completely re-drew the county subdivision boundaries; in these cases the NOTES column uses the term "Redistricted" to indicate a lack of any relationship. Tennessee changed its county subdivisions from statistical census county divisions (CCDs) to legal County Commissioner Districts and there is no comparability for any Tennessee county subdivisions.

All relationships are based on a preliminary compilation and review of data; some changes may appear in later products.  The Census Bureau, however, believes this file to be overwhelmingly accurate, and is releasing this preliminary version in response to requests for information about county subdivision relationships.  The final version of this file is expected to be released in the first quarter of 2012.

Place Relationship File

The place relationship file provides a simple relationship between each 2010 place (incorporated place, census designated place [CDP], or consolidated city) and its comparable 2000 place with an additional comments section to describe more detailed changes. For the vast majority of records, there is a one-to-one relationship between a 2010 place and a 2000 place, although names and codes may have changed between censuses. Where a 2010 record has no comparable 2000 place information, most of the 2010 places are newly defined from area not in a place, but the Comments column provides additional information if required.

Comparability for incorporated places is based on continuing governmental status; there may have been substantial boundary changes or other changes that modified the boundaries. For CDPs, comparability is based on the CDP still being defined for its "core" area as determined by local participants and through points identified in the Geographic Names Information System developed to support the U.S. Board on Geographic Names as the official repository of domestic geographic names data. As with incorporated places, comparability implies continuity of definition, but the actual area of a CDP may have changed between 2000 and 2010.

Tract Relationship Files

The 2010 Census Tract Relationship files are provided as a tool to help data users compare the universe of Census 2000 tracts to the universe of 2010 Census tracts. From these files, data users may determine how Census 2000 tracts relate to 2010 Census tracts and vice versa. The links below provide more information about the relationship files, including format and layouts, as well as a link to the files. Also see the Congressional District relationship files section above for the 113th Congressional Districts to Census Tract relationship files.

Urban Areas Relationship Files

The 2010 urban area relationship file describes the relationship between 2010 and Census 2000 urban areas.

For more information on urban areas, please see our Urban and Rural Classification page.

For more information on specific Geographies, please see the 2010 Census Geographic Terms and Concepts.

 

Geographic Relationships Between Entity Types

These files show the relationship between different types of geography for the same time period (e.g. the relationships between congressional districts and places).

Census Tract Relationship Files

The Census Tract Relationship files provide simple relationships between the 2010 Census Tracts and the specified geographies.

Congressional District Relationship Files

The Congressional District Relationship files provide simple relationships between the specified Congressional District and other Census 2000 and 2010 Census tabulation geography including American Indian areas, counties, county subdivisions, census tracts, places, school districts, urban/rural population and land area, and ZIP Code Tabulation Areas. The links below provide more information about the relationship files, including format and layouts, as well as a link to the files.

State Legislative District Relationship Files

The State Legislative District Relationship files provide simple relationships between the specified state legislative district (upper house or lower house) and 2010 Census tabulation geography including American Indian areas, counties, county subdivisions, census tracts, places, school districts, urban/rural population and land area, and ZIP Code Tabulation Areas. The links below provide more information about the relationship files, including format and layouts, as well as a link to the files.

Urban Area Relationship Files

The 2010 urban area relationship files provide simple relationships between the 2010 urban areas and other 2010 Census tabulation geography: counties, county subdivisions (in states with governmental minor civil divisions only), places (incorporated places and census designated places), metropolitan and micropolitan statistical areas, New England city and town metropolitan and micropolitan statistical areas (NECTAs), and ZIP Code tabulation areas (ZCTAs). A 2010 urban area relationship file also describes the relationship between 2010 and Census 2000 urban areas. From these files, data users may determine which urban areas exist within the other geographies and vice versa. Also see the Congressional District relationship files section above for the 113th Congressional Districts to Urban/Rural Population and Land Area relationship files.

For more information on urban areas, please see our Urban and Rural Classification page.

For more information on specific Geographies, please see the 2010 Census Geographic Terms and Concepts.

ZIP Code Tabulation Area (ZCTA) Relationship Files

The 2010 ZIP Code Tabulation Area (ZCTA) Relationship files provide simple relationships between the 2010 ZCTAs and other 2010 Census tabulation geography. From these files, data users may determine which ZCTAs exist within the other geographies and vice versa. Please use the links below to find out more about the 2010 ZCTA Relationship files. Also see the Congressional District relationship files section above for the 113th Congressional Districts to ZCTA relationship files.


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Source: U.S. Census Bureau | Geography | (301) 763-1128 |  Last Revised: January 03, 2014