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 1990 Census data are separated into three basic types: Summary Tape Files, Public Law (P.L.) 94-171 data, and Public Use Microdata Samples (PUMS). Within these collections, various data subsets are available, depending on the user's needs. In addition, several special tabulations based on the 1990 Census are available, including the Equal Employment Opportunity Special File; Extract Data; Public Law (P.L.) 94-171 Data; Special Tabulation Program (STP) 14A, Special Tabulation on Aging; TIGER/Census Tract File; and Modified Age/Race, Sex, and Hispanic Origin (MARS) State and County File. Summary Tape Files include files in the Summary Tape File 1 (STF 1), Summary Tape File 2 (STF 2), Summary Tape File 3 (STF 3), and Summary Tape File 4 (STF 4) series. The Summary Tape Files contain 100-percent data on population and housing. The record layout is identical for all the four series but the geographic coverage differs. Data are provided for states and their subareas in hierarchical sequence down to the block group level. Public Law (P.L.) 94-171 data provide 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. Public Use Microdata Samples (PUMS) were creatd by the Census Bureau since 1960 as part of each decennial enumeration. PUMS make it possible for researchers to create tabulations tailored to their particular questions and to make time-series comparisons. Public Use Microdata Samples (PUMS) for the 1990 Census contain records representing 5 percent and 1 percent samples of the housing units in the U.S., with information on the characteristics of each unit and the people in them. Both the 5 percent and 1 percent samples have the same subject content and vary only in geographic composition of the Public Use Microdata Area (PUMA).