Factors to Consider in Census Data Research

There are three different things to have in mind as you search Census statistical data.

1.   Date:   Censuses are taken once every ten years.   Sometimes the tables in Census reports record statistics from multiple decades, but very seldom are data for smaller geographies or specific subjects presented over a long period of time in a single volume.

The Historical Census Browser can help you find data contained in multiple censuses. That resource and other multi-year compilations of census data are described in the Multi-Year Statistical Resources page.

2.   Geography:   We all know some Census geographies:   state, county, city or town.   But Census figures are also reported at geographic levels that are less-well known.   Data for small geographies like "tracts," "block groups," and "blocks" can be even more significant to planners and researchers than data reported at larger geographic units.

These resources will help you learn about Census geographies.
   1.   1990 Metropolitan Area graphic
   2.   Census Small-Area Geography, p. 2 of a 4 page PDF
   3.   Census Geography page from Census Factfinder
   4.   Census 2000 Geographic Terms and Concepts, a 27 page PDF

3.   Topic:   Finding the type of data that you want within Census documents can be tricky.   The questions asked in censuses have changed over time, and more recent censuses record data on more topics than did earlier ones.   Also the topic you're interested in may not be one that was addressed by a census questionnaire.

General tips to locate topical statistics:
  1.   This guide's pages describing decennial Census resources summarize the questions asked and contain a link to the decade's questionnaire.
  2.   "Table Finding Guides" are contained in printed volumes that identify the subjects found in specific tables. There is such a finding guide in the 1850 volume, but this aid does not make a reappearance until 1930.
  3.   For the 1990 and 2000 censuses, the electronic resources lead you through a series of steps by which you choose desired geographies and topics to display.