OVERVIEW

Welcome to the Archive of Census Related Products. The archive is a collection of georeferenced data files containing census information that spans the United States and its territories. This coverage will expand to include Mexico and Canada, establishing a North American repository for population, land use, and emissions data and integrated data products. These data are value-added products derived from original census files compiled by the U.S. Bureau of the Census. The major components are:

TIGER - boundary files based on TIGER 1992 files containing U.S. census geographies.

STF - demographic data files containing population and housing characteristics from the 1990 Summary Tape File STF3A and STF1B.

STP - migration files derived from the STP28 Special Tabulation for 1990 which show the movement of persons by county.

GRID - grid files combine population data with land cover data. Population data were derived from the 1990 U.S. Census at the blockgroup level. The Land Cover Characteristics database was derived from 1990 satellite data. The result is an integrated datafile containing a coverage extent, grid cell size, and population, housing, and land cover attributes for each square kilometer grid cell. Image files are included to display the data by region.

PUMS - public-use microdata samples which provide information for a sample of housing units with data on the characteristics of each unit and the people in it. The data are 5% and 1% samples of the population and housing of the United States.

Availability

These data files and accompanying documentation are available via:

• Request to CIESIN User Services at ciesin.info@ciesin.org (CD-ROM copies are available upon request)
• FTP
• WWW

Access to the Archive: How do I get the data ??

You can establish an ftp session via an Internet connection.

• ftp to ftp.ciesin.org
  • login name: anonymous
  • password: your email address
  • cd /pub/census
  • (you should see a message describing the census directories)
    
    
    • FTP commands: cd, lcd, prompt, mget, bi, bye
    • cd - is the command that lets you "change directory" example: cd usa
    • lcd - is the command that lets you change the current directory on your local host.
    • prompt - turns off the message that asks you to respond "Y/N?" to get each file.
    • mget - is a command that lets you retrieve multiple files.
    • bi - binary, use this mode for binary transfer
    • bye - terminates ftp session and exit ftp.
    
    
    • Example: If you want to get all of the readme files for the archive. Follow the login instructions outlined for FTP to ftp.ciesin.org. Once you are in the /pub/census directory, proceed with the steps listed:
      • Transfer mode: ascii for text files binary for programs, zipped files, etc.
      • At the FTP> cd .support The /pub/census/usa/.support contains all of the archive readme files.
      • At the FTP> lcd Change working directory on local host.
      • At the FTP> prompt mget *
      • At the FTP> mget * All of the files should start to transfer into your current directory on your local disk.
• Web browser
  • U. S. Demography Home Page
  • URL http://www.ciesin.org/datasets/us-demog/us-demog-home.html
  • Click on the anonymous ftp link to register and access the archive
  or
  • Integrated Population, Land Use, and Emissions Data Project
  • URL http://sedac.ciesin.org/plue
  • Click on the anonymous ftp link to register and access the archive

Organization of the Archive

• The United States census data is organized under the "usa" directory. The next level shows the major branches (tiger, stf, stp, grid, pums) which are organized by state.
• There are readme and content files in each directory to explain the content and file names. A diagram showing the directory structure of the entire archive can be found in /pub/census/dtree.txt .
• The file naming convention is consistent across the states.
• The executable binaries used to unzip files on multiple platforms and license information are provided in the /pub/census/src directory.
• Documentation (readme) that describes the data, the filenaming convention, and directories is available in the /pub/census/.support directory. You can retrieve every readme for all of the data that is stored in the archive when you issue the "mget * " command in the .support directory. Text documents describing variables, format processing and information about the data can also be found in the /pub/census/.support/infofiles directory. All of the supporting documentation can be retrieved by issuing the "mget *" command in the .support/infofiles directory.
• The program source code for converting the data to different formats and for use across multiple platforms can be found in the /0code directory of under the major branch of the tiger, stf, stp and zip equivalency data directories.
• In each major branch of the archive: tiger, stf, grid, you can retrieve files covering the entire United States. The breakdown is by state, county, puma, mcd, place, tract, blockgroup, and block. In addition, the 1980 minor civil divisions and tr act files are included. Look for these data in the /us directory.

ARCHIVE ANNOUNCEMENTS

• The introduction of the archive to the public with a description of the contents starting Feb. 1, 1995 as well as updates can be found in /pub/census in the file archive.ann.
  
• For current information about the archive, problems, and bug fixes, see the whatsnew.txt file.