Products Overview

The lowest level of geography for summary data from 1970 is either block groups (in areas were tracts were defined) or elsewhere enumeration districts (ED). This overview outlines how key products were originally published and highlights only a few of the custom products that were subsequently produced based on the original. The Data Sources section that follows focuses on the best available sources which may be products derived from the originals.

• Summary Files
   
  The table below outlines the most commonly used summary files from the 1970. Not all these files are readily available. For some that are all states may not be reported. 1st and 2nd Count files are based on 100% counts while 4th and 5th Count data are sample data. Breakdowns within each of these files are shown below and are based on the geographic concept of "summary level." Summary level and other technical concepts pertaining to summary files are briefly described in the EDS guide, Census Summary Files: Technical Issues.
   
  

  First Count      1A: States and EDs      1B: States, counties, CCDs, MCDs,           & CDs	Fourth Count      4A: States-Tracts      4B: States-MCDs-CCDs      4C: States-MSA-Urban areas
  Second Count      1A: States and tracts      1AB: States, counties, CCDs, MCDs,           & CDs	Fifth Count      5A: 3 digit Zip Code      5B: 5 digit Zip Codes by SMSA      5C: States-Tracts-Block Group/EDs

  
  Some sample questions were asked of either a 15% or a 5% sample of households, but some were asked for both, thus constituting a 20% sample. Variation can occur among totals based responses from 20%, 15% or 5% samples.
• Other Summary File Products
  Special subsets based on either geography or topic have been created from the Summary Files. When needs can be met with these files, they are easier to use than the original files. Also there are the Elizabeth Bogue Census Tract Files for which data was keyed in from the printed tract reports for selected metropolitan areas.
• Public Use Microdata
  Public Use Microdata were produced and reported for county groups, states, and geographic divisions with neighborhood characteristics each with a population of at least 250,000. Originally the files were hierarchical (contain both household and person records). A modified version is also available that combines household and person data on record so that the file is rectangular.
• Maps
  Columbia's holdings for 1970 maps are described on the Government Documents 1970 Decennial Census Information web page.

Data Sources

• Files for FTP
  If using the ascii versions of the summary files, users should acquaint themselves with how certain Technical Issues are handled. Suppression and allocation are issues of particular interest to those dealing with tract level or smaller geographies.
  • ICPSR
    Provides the most complete archive of 1970 files including a number of special extractions produced by the Census Bureau for easier access for some geographic areas and the Elizabeth Bogue tract data files for selected metropolitan areas (does not include NYC).
  • DataGate
    Selected files (especially for New York City counties) are available. Search DataGate for study number 1970 to see what is available.
• Online Extraction Data
  • National Historical Geographic Information System (NHGIS)
    NHGIS provides an online extraction tool for selected summary file variables at the national, state, county, and tract/block numbering areas allowing for multiple locations at one level of geography to be downloaded at once
  • Integrated Public Use Microdata Series (IPUMS)
    At this site custom extractions of public use microdata can be done. Coverage is for all census years since 1850 except 1930.
• CD-ROM Products from Geolytics
  These products come with easy-to-use software that extract data for use in statistical packages, for making thematic maps, or for importing in to GIS software. It is available on the DSSC machines in Data Apps folder within the Program Menu.
     -1970 CensusCD (data to the block group level, no ZIP codes)
     -Neighborhood Change Database (1970 data using 2000 tract boundaries)
• Spatial Data
  
  • 1970 CensusCD (available on the DSSC machines)
    Spatial files can be exported with data from this product.
  • National Historical Geographic Information System (NHGIS)
    NHGIS is a project to create and freely disseminate a database incorporating all available aggregate census information for the United States between 1790 and 2000. You can download tract boundary files by state

General Information

• Library's Collection
  This is a detailed list of Columbia's print and CD-ROM holdings plus links to useful Web sites and reference sources.
• Obtaining Data by Congressional District
• Historical Census Data Tables
  The Census Bureau has published a number of tables covering all census years. In addition to basic counts of people and housing, there are selected special topics included.
• National Archives and Records Administration (NARA)
  Together with listing of their electronic holdings (which are available at cost), the NARA provides descriptive information about each file.
• Comparing 1970 and with other Census years
  • Significant Changes to Counties: 1970-Present
    Summarizes the changes to boundaries for counties or county equivalent areas deemed to be significant because of either population affected or land area involved.
  • Tract Comparison Tables, New York City
    Excel spreadsheets that cover the tract changes between 1970-1980-1990-2000.
• Related reference material
  • Geographic Areas Reference Manual
    Although focused on the 1990 Census this book provides a history of census geography and including information about areas like, MCDs, CCDs, outlying areas, Indian lands, and blocks. This book is also available in print in EDS and in CLIO.
  • Measuring America: The Decennial Censuses From 1790 to 2000
    Contains questionnaires and instructions, plus individual histories of each census as well as a chart listing topics covered in each census year. This book is also available in print in EDS and in CLIO.
  • Background Information About Census
    This site is part of the Historical Census Browser site and it provides a useful synopsis of the information found in the publication, 200 Years of Census Taking: Population and Housing Questions, 1790-1990. Washington, DC: Bureau of the Census, 1989 which is available in Lehman's U.S. government documents collection, call number, C 3.2:T 93.
  • Decennial Census Information General Census Monographs
    This is a list of other publication on the subject of the Decennial Census.