Census Geography

Many data are available only for the state, counties and municipalities. However, 1990 census data can be found here for all the entities mentioned below.

• The State - the only state currently available from the system is Wisconsin
• Counties - There are 72 counties in Wisconsin. There is no part of the state that is not in a county.
• Municipalities, also known as Minor Civil Divisions (MCDs) are the cities, towns and villages into which all Wisconsin counties are divided. Some cities and villages (but no towns) cross county boundaries, and each one-county segment is viewed as a separate MCD. In Wisconsin, there is no part of a county that is not in an MCD.
• Tracts and Block Numbering Areas (BNAs) are relatively small statistical subdivisions of counties. Their boundaries do not necessarily correspond with those of MCDs.
  • Census tracts are delineated for metropolitan areas and other densely packed counties. They generally have between 2,500 and 8,000 persons.
  • BNAs are the equivalent in non-metropolitan counties.
• Block Groups are clusters of blocks having the same first digit of their 3-digit code; blocks are the smallest unit of geography for which census data is collected.
• Places are entire incorporated areas (cities and villages) and may overlap parts of more than one county.