U.S. Census of Population and Housing Basics : Census Geography

More detailed information about census geography can be found at the following sites:

• Glossary of geographic terms from the Geography Program
• American Community Survey
  • Geography and ACS
    • The Concepts and Definitions section has information on the most commonly used "Geographic hierarchy"
• Metropolitan and Micropolitan Statistical Areas (glossary; need to scroll down to "M" section for definitions of "metropolitan" and "micropolitan"

The following diagram outlines the divisions of census geography, from the nation as a whole to the census block.

When retrieving Census data, you'll be asked what geographic level you want the data from, whether for the whole U.S., or for Census blocks.

Not all data are available for every kind of geography.

Data becomes available for different geographic levels at different times.