Investigator(s): U.S. Bureau of the Census
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. ICPSR's holdings of 1970 Census data include a variety of data files acquired from the United States Census Bureau, a national-coverage file prepared by ICPSR, and files prepared by other principal investigators. The files from the Census Bureau are separated into three basic types: Summary Count files, the Master Enumeration District List (MEDList) files, and Public Use Microdata Samples (PUMS). Within these collections, various data subsets are available, depending on the user's needs. For example, to obtain first-count data for Minnesota's Congressional Districts, the user can download ICPSR 8122, Summary Count 1B for Minnesota. In addition, ICPSR 0003 contains a subset of 1970 data that might be useful for users of the 1970 Census of Population and Housing. This subset, the National Coverage file, contains all the variables published in the "Advance Report of the General Population Characteristics" obtained from the First Count of the 1970 Census. The information in this file is presented for all counties and states in the United States. ICPSR's holdings of the Summary Count files include Summary Count File 1B (all states), Summary Count File 4A--Population (all states), Summary Count File 4B--Population (most states), Summary Count File 4C--Population (all states), and Summary Count 4A--Population and Housing (California). Summary Count Files present tabulations for small geographic areas. First Count Summary Files contain about 400 cells of final complete-count population and housing data, summarized in File A for enumeration districts or blockgroups, and in File B for states, counties, minor civil divisions (MCDs) or census county divisions (CCDs), places, and congressional districts. Second Count Summary Files are subdivided into File A and File B and contain about 3,500 cells of complete-count population and housing data summarized for each census tract in File A, and for states, counties, MCDs or CCDs, places, and Standard Metropolitan Statistical Areas (SMSAs) in File B. Third Count Summary Files contain 250 cells of complete-count population and housing data for each city block in urbanized areas and other areas which have contracted for block statistics. Fourth Count Summary Files contain 20-, 15-, and 5-percent sample population and housing characteristics organized into three file subdivisions. Fifth Count Summary Files contain population and housing sample data summaries for ZIP code areas. Sixth Count Summary Files provide detailed tabulations and cross-classifications of sample population and housing characteristics for states, SMSAs (metropolitan counties), nonmetropolitan counties of 50,000, and larger cities. The Master Enumeration District List (MEDList) files provide information for geographic codes contained on census summary tapes. They provide a listing of state, county, and area or place names corresponding to numerical identification codes used on the summary tapes. The 1970 MEDList is an expanded version of the 1960 Geographic Identification Code Scheme but unlike the 1960 counterpart, the 1970 MEDList contains block and census tract codes, enumeration district codes, and population and housing totals for enumeration district and block groups from which congressional district and other area totals may be summarized. Public Use Microdata Samples (PUMS) were created by the Census Bureau since 1960 as part of each decennial enumeration and contain individual- and household-level information from the long-form questionnaires distributed to a sample of the population enumerated in the Census. The PUMS make it possible for researchers to create tabulations tailored to their particular questions and to make time-series comparisons. In 1970, the Bureau produced three geographic versions and created a Form 1 sample and a Form 2 sample for each version: the state samples, the metro or county group samples, and the neighborhood samples. The state and county group samples have two record types: housing unit records and person records. For each household, information is provided on the housing unit itself, as well as on the characteristics of each person in it. Each housing unit record is followed by a variable number of person records, one for each member of the household or none if a unit is vacant. A third record type is also present in the neighborhood characteristics samples: each neighborhood characteristic record is followed by the housing unit records sampled within the neighborhood, which in turn are associated with person records. Because of confidentiality reasons, the 1970 samples do not identify any places smaller than 250,000 inhabitants.
For more information, visit the IPUMS USA Web site.