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 2000 Geographic Terms and Concepts (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.