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.
Note that 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.
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.
2nd Count A: States and Tracts B: States, counties, MSAs and places
Long form, Sample count- estimates
4th Count A: States-Tracts B: States-MCDs-CCDs C: States-MSA-Urban areas
5th Count A: 3 digit Zip Code B: 5 digit Zip Codes by SMSA C: States-Tracts-Block Group/EDs
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.
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.
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).
CU Data Catalog
Selected files (especially for New York City counties) are available. Search the data catalog for study number 1970 to see what is available.
Online Extraction Data
Use Data & Tools then choose Browse Reports to obtain selected tables for years including 1970.
Longitudinal Tract Data Base (LTDB)
Preselected 1970 population characteristics in Excel spreadsheets reported for tracts as defined in 1970 or as defined in 2010. LTDB also has a feature that allows you to adjust any data based on 1970 tracts to estimates based on 2010 tracts.
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.
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 the Data Service and in CLIO.