Demographic Census information includes data about people and their housing conditions, obtained from decennial Census questionnaires that are administered every 10 years. This activity is mandated by the Constitution, which requires decennial counts of the population in order to apportion legislative districts. Over the years, of course, this data has also become important for all kinds of other government programs, as well as for sociological and economics research by businesses and in academia.
For the last few Censuses, the Blume Library has received printed copies of the major decennial Census series, for all 50 states, as well as some CDs/DVDs with additional data files. Most of this material is in printed form, although some is also in microfiche.
Earlier Census data (1960-70) was received only for Texas. Our holdings for even older Censuses is very scattered and only compendia and some subject monographs are available. What we have is listed in detail under the Older Censuses page.
Since Census material in the Library is held in several different formats, and the format options might influence a researcher's choices in accessing this data, we've attached icons in this guide to indicate in which format different series are available. Also, we have provided links when the information is available digitally, either through Census.gov or some other reliable digitized collection.
Data at Census.gov is available in a variety of formats. Much basic information is provided on normal web pages, through drop-down menus and other devices (for some data to display, Java must be enabled). More extensive files might be available for download in spreadsheet or PDF format. Electronic versions of publications such as documentation and historical reports are usually in PDF format.
As required by the Constitution, the Census Bureau conducts a complete count of residents of the U.S. every ten years. Simple counts of people in states and areas must be available by the beginning of the year following the Census because this data is used to apportion Congressional seats. The other data (income, education, etc.) generated by the Census surveys usually takes a few years to become available. This detailed data, giving social and economic characteristics of the population of small geographical areas, is usually not available until at least three years after the Census was taken.
The more detailed the statistics one searches for, the less detailed are the geographical areas for which the statistics are available. For example, in past Censuses, general population counts were published for places as small as 1,000 people. But poverty status figures were given only for places as small as 2,500. Detailed cross-tabulations of poverty status and educational level may only be given for large (more than 250,000) cities. Thus, two parameters are important when selecting a Census report to study: the kind of statistics one needs, and the geographical area of interest. For more information on Census geography, see the Geography page.
Information contained in the Census volumes is collected from questionnaire responses. Some basic information (e.g.: age, sex, race) is obtained from all residents, whereas other, more detailed questions (e.g.: income, education, employment status) are only asked of a sample. And some questions are not asked at all, (for example, "what is your religion?") which means that no data on these subjects is available from the Census Bureau. For more information on the importance of Census methodology, see the Comparability page.