The following links lead to Census documentation describing how the Census collects data, models of Census geography and terms and concepts used in Census Questionnaires.
Note that changes in Census methodology over time will impact comparisons between Censuses.
American FactFinder Reference Shelf
Data and map publications from the Census Department.
U.S. Postal Service Zip Code (U.S. Postal Service)
Zip Code look-up web site. Note zip codes can change over time when comparing earlier data.
The Census Department distributes data for various geographic areas up to the national level. Click on the link below to see a diagram which displays geographic areas from the smallest to the largest.
Census Geography Full Image
Census Geographiy Sources (U.S. Census Bureau)
Links to a glossary of terminology used in the collection of the Census 2000 data including racial categories. Gives descriptions and hierarchy of Census geography from the block level to the national level. Click to download PDF file.