The U. S. Census uses many spatial units to analyze and aggregate data. Below are examples of the different units available through NHGIS, listed in order of scale:
SEE ALSO Note on using Spatial Data
*Units marked with an asterisk may be larger than, or cross boundaries of larger scale units
About : The United States is divided into four regions: Northeast , South, Midwest, and West (including Alaska and Hawaii).
Spatial Scope : United States and the District of Columbia. Does not include Puerto Rico other territories and dependencies
Use: Regions are used as analytic units in the Decennial Census, American Community Survey (ACS), Current Population Survey (CPS), Economic Census, Survey of Business Owners (SBO), and the Population Estimates Program.
About : The United States is divided into 85,074 tracts. A detail of Baltimore City is shown above.
Spatial Scope : 50 United States, the District of Columbia and Puerto Rico.
Use: Tracts are used as analytic units in the Decennial Census, American Community Survey (ACS), Current Population Survey (CPS), Economic Census, Survey of Business Owners (SBO), and the Population Estimates Program.
About : The United States is divided into 242,180 block groups in 2020. A detail of Baltimore City is shown above.
Spatial Scope : 50 United States, the District of Columbia and Puerto Rico.
Use: Census block groups are used as analytic units in the Decennial Census, American Community Survey (ACS), Current Population Survey (CPS), Economic Census, Survey of Business Owners (SBO), and the Population Estimates Program.
About : Census blocks are the smallest spatial analytic unit produced by he U. S. Census Bureau. The United States is divided into 8,180,866 blocks in 2020. A detail of Baltimore City is shown above.
Spatial Scope : 50 United States, the District of Columbia and Puerto Rico.
Use: Census block groups are used as analytic units in the Decennial Census, American Community Survey (ACS), Current Population Survey (CPS), Economic Census, Survey of Business Owners (SBO), and the Population Estimates Program.
