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TIGER (Topologically Integrated Geographic Encoding and Referencing) refers to the system and digital data base developed at the Census Bureau to support its mapping needs for the Decennial Census and other Bureau programs. Every 1-3 years the Census Bureau creates an extract from this data base and makes it available on CD-ROM in raw TIGER format. These extracts are known as TIGER/Line files. The Libraries obtain the raw TIGER data as well as value-added versions of the data in, for example, ArcView shapefile format. TIGER data includes political and census boundaries that can be used in conjunction with tabular data. TIGER also includes a wide range of feature data at a 1:100,000 scale. TIGER data is in geographic coordinates/decimal degrees and, starting with the 1995 release, TIGER uses the NAD 83 datum. [see the TIGER Overview]
TIGER 2002 data is available in raw format from: Census Bureau TIGER page.
TIGER 2000 data is available as shapefiles for public access from: ESRI's Census 2000 TIGER/Line Data Download Page. Selected SF1 attributes may also be downloaded and joined to the shapefiles. See the Census 2000 page for additional information and sources of data.
From ESRI's Census Data Download FAQ's:
What's the difference between the data on the ESRI Web site and
the data on the Census Web site?
For the cartographic boundary files, the data from the Census site
have been generalized from the original TIGER/Line data, whereas the
files downloaded from ESRI still maintain the original detail.
Files on the Census site can also be downloaded by state and/or for
the entire nation, depending on the layer. So if the generalization
is acceptable, the Census site is the best source for large amounts
of data. The Census Bureau (www.census.gov) also offers the files
as shapefiles, Arc Info export files (.e00), and Arc Info ungenerate
(ASCII) files.
For other geographic files (water, etc.) and for the attribute
tables (PL-94 and SF1) that can be downloaded from ESRI, the Census
site does not offer downloadable files that are ready to use with
ESRI software. These geographic files are available only in TIGER
format, so they have to be converted into a coverage or shapefile.
The attribute files can only be downloaded from the Census site as
huge text files that have to be reformatted, and that contain
hundreds of attributes per file. ESRI extracted from these huge
files only the attributes that were wanted and assigned meaningful
names to the fields in the tables.
TIGER data for 1970 through 2000 may be extracted using the Libraries' GeoLytics software. Alternatively, contact Michele Hayslett for information about earlier versions of TIGER data available at D. H. Hill Library.
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