ARCDBA.Census_Tract_2000_Poly

TIGER, TIGER/Line, and Census TIGER are registered trademarks of the U.S. Census Bureau.  ZCTA is a trademark of the U.S. Census Bureau. The Census 2000 TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER data base.  The geographic coverage for a single TIGER/Line file is a county or statistical equivalent entity, with the coverage area based on January 1, 2000 legal boundaries.  A complete set of Census 2000 TIGER/Line files includes all counties and statistically equivalent entities in the United States, Puerto Rico, and the Island Areas.  The Census TIGER data base represents a seamless national file with no overlaps or gaps between parts.  However, each county-based TIGER/Line file is designed to stand alone as an independent data set or the files can be combined to cover the whole Nation.  The Census 2000 TIGER/Line files consist of line segments representing physical features and governmental and statistical boundaries.  The boundary information in the TIGER/Line files are for statistical data collection and tabulation purposes only; their depiction and designation for statistical purposes does not constitute a determination of jurisditional authority or rights of ownership or entitlement.  The Census 2000 TIGER/Line files do NOT contain the Census 2000 urban areas which have not yet been delineated.  The files contain information distributed over a series of record types for the spatial objects of a county.  There are 17 record types, including the basic data record, the shape coordinate points, and geographic codes that can be used with appropriate software to prepare maps.  Other geographic information contained in the files includes attributes such as feature identifiers/census feature class codes (CFCC) used to differentiate feature types, address ranges and ZIP Codes, codes for legal and statistical entities, latitude/longitude coordinates of linear and point features, landmark point features, area landmarks, key geographic features, and area boundaries.  The Census 2000 TIGER/Line data dictionary contains a complete list of all the fields in the 17 record types.

The Census shapes were altered my M-NCPPC staff so that it conformed to the 1:2,400 base mapping.

In order for others to use the information in the Census TIGER data base in a geographic information system (GIS) or for other geographic applications, the Census Bureau releases to the public extracts of the data base in the form of TIGER/Line files.  Various versions of the TIGER/Line files have been released; previous versions include the 1990 Census TIGER/Line files, the 1992 TIGER/Line files, the 1994 TIGER/Line files, the 1995 TIGER/Line files, the 1997 TIGER/Line files, the 1998 TIGER/Line files, the 1999 TIGER/Line files, and the Redistricting Census 2000 TIGER/Line files.

To find out more about TIGER/Line files and other Census TIGER data base derived data sets visit http://www.census.gov/geo/www/tiger.

The information present in these files is provided for the purposes of statistical analysis and census operations only.  Coordinates in the TIGER/Line files have six implied decimal places, but the positional accuracy of these coordinates is not as great as the six decimal places suggest.  The positional accuracy varies with the source materials used, but generally the information is no better than the established national map Accuracy standards for 1:100,000-scale maps from the U.S. Geological Survey (USGS); thus it is NOT suitable for high-precision measurement applications such as engineering problems, property transfers, or other uses that might require highly accurate measurements of the earth's surface.  The USGS 1:100,000-scale maps met national map accuracy standards and use coordinates defined by the North American Datum, 1983.  For the contiguous 48 States, the cartographic fidelity of most of the Census 2000 TIGER/Line files, in areas outside the 1980 census Geographic Base File/Dual Independent map Encoding (GBF/DIME) file coverage and selected other large metropolitan areas, compare favorably with the USGS 1:100,000-scale maps.  The Census Bureau cannot specify the accuracy of features inside of what was the 1980 GBF/DIME-File coverage or selected metropolitan areas.  The Census Bureau added updates to the TIGER/Line files that enumerators annotated on maps sheets prepared from the Census TIGER data base as they attempted to traverse every street feature shown on the Census 2000 map sheets; the Census Bureau also made other corrections from updated map sheets supplied by local participants for Census Bureau programs.  The locational accuracy of these updates is of unknown quality.  In addition to the Federal, State, and local sources, portions of the files may contain information obtained in part from maps and other materials prepared by private companies.  Despite the fact the TIGER/Line data positional accuracy is not as high as the coordinate values imply, the six-decimal place precision is useful when producing maps.  The precision allows features that are next to each other on the ground to be placed in the correct position, on the map, relative to each other, without overlap.