Summary: | In addition to the historic Census files, 1790-1950,
ICPSR archives and distributes Census data acquired from the
United States Census Bureau as well as files prepared by ICPSR
and other principal investigators for the decennial years 1960,
1970, 1980, 1990, and 2000. These include major sets such as
the Summary Tape/Count Files, Master Enumeration District
List (MEDList) files, and Public Use Microdata Samples (PUMS),
as well as various subsets. For the 2000 Census of Population
and Housing, and with funding from the National Science
Foundation and the National Institutes of Health, ICPSR
distributes files from the following Census components:
P.L. 94-171 Redistricting Files, Summary File 1 - Advanced
National, Final National, and States, Summary File 2 - Advanced
National and States, Summary File 3 - States and National. In
addition, ICPSR has created subsets from Summary File 1,
Advanced National, and Summary File 1, States, in order to
facilitate analyses of the data. Each subset comprises all of the
cases in one of seven census summary levels: the nation, states,
counties, places, five-digit ZIP code tabulation areas, whole
census tracts, and census tracts in places. Summary Files 1
and 2 (SF 1 and SF 2) contain the 100-percent data, which is
the information compiled from the questions asked of all people
and about every housing unit. They include population and
housing characteristics. Selected aggregates and medians are
also provided. SF 1 and SF 2 National files provide summaries
for the entire United States, as well as for regions, divisions,
states, counties, county subdivisions, places, American Indian
and Alaska Native areas, tribal subdivisions, and metropolitan
areas. The final national file includes data for urban (urbanized
areas and urban clusters) and rural areas. Summary File 3 (SF 3)
contains the sample data, which is the information compiled
from the questions asked of a sample of all people and housing
units. Summary files are released as individual files for each of
the 50 states, the District of Columbia, Puerto Rico, and the
United States. The 2000 Census Tract Relationship Files (CTRF)
assist users in determining the relationship between 1990 and
2000 census tracts. They consist of four sets of files. Public
Law (P.L.) 94-171 data provide states with data for voting
districts (e.g., election precincts, city wards) in addition to
standard census geographic areas such as counties, cities,
census tracts, and blocks, in accordance with the requirement
of the 1975 Public Law 94-171 which mandates the Census
Bureau to provide redistricting data in a format requested
by state governments. The 1998 Dress Rehearsal, P.L.
94-171, was conducted as a prelude to the United States
Census of Population and Housing, 2000, in selected
locations. The Profiles of General Demographic
Characteristics contain the 100-percent data, which is the
information compiled from questions asked of all people
and about every housing unit. ICPSR has an agreement with
the Census Bureau to distribute all of Census 2000 data plus
the maps. For further information and access to integrated decennial
census data see the IPUMS USA
Web site. |
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