Interactive Apportionment Map Now Available

Interactive Apportionment Map Now Available

Apportionment Data Viz

The U.S. Census Bureau launched a new online map today ahead of the 2020 Census apportionment results release. The “Historical Apportionment Data Map” currently displays apportionment results for each census from 1910 to 2010.

The 2020 Census apportionment results will be added to the map as they become available. The Census Bureau plans to release apportionment counts by April 30.

The interactive map includes the following types of data for each census from 1910 to 2010:

  • Number of seats in the U.S. House of Representatives.
  • Changes to each state’s number of seats in the U.S. House of Representatives.
  • Population per representative for each state.
  • Resident population of each state.
  • Percentage change in resident population for each state.
  • Population density of each state.

See the Map

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Apportionment 101

Every 10 years, population counts from the decennial census determine how many seats each state gets in the U.S. House of Representatives. This process, called apportionment, is one
of the most important uses of census results because it impacts your voice in Congress.

Learn more in our Apportionment 101 fact sheet. Download it in English or one of 13 other languages and share it!

Apportionment FAQs

What is apportionment?

Who is included in the apportionment population counts?

How is the apportionment calculated?

What is the difference between apportionment and redistricting?

You have questions, we have answers. Visit our website for answers to some of the most frequently asked questions about apportionment.