Congressional Apportionment by State
-- 2010 & 2020 state by state congressional seats
April 2021 .. view the first results of Census 2020 and how the House of Representatives will be reapportioned, state by state, released April 26, 2021. How might the 2020 apportionment affect you? The U.S. resident population represents the total number of people living in the 50 states and the District of Columbia. The resident population increased by 22,703,743 or 7.4% from 308,745,538 in 2010.
While many will view these data as the basis for reapportionment, which they are, they are more than this. These data are also the official state population totals which will be used for the development of demographic data throughout the 2020's and beyond. These data are our first definitive look at how the U.S. and individual states changed in terms of total population from 2010 to 2020 .. providing a baseline for how these areas might change into the future.
There are really two Census 2020 population numbers released for each state: the resident population and the apportionment population. The apportionment population includes the resident population for the 50 states, as determined by Census 2020 and counts of U.S. military and federal civilian employees living overseas (and their dependents living with them overseas) allocated to their home state, as reported by the employing federal agencies. Overseas is defined as any location outside the 50 United States and the District of Columbia. The apportionment population excludes the population of the District of Columbia and Puerto Rico.
- view interactive 2010/2020 apportionment table below
- use the GIS tools and project to make your own map views ... see below
Apportionment of the U.S. House of Representatives
-- based on the 2020 Census
- view created with ProximityOne CV XE GIS. Click graphic for larger view with more detail.
Congressional apportionment is the process of dividing the 435 members, or seats, in the House of Representatives among the 50 states based on the population figures collected during the decennial census. The number of seats in the House has grown with the country. Congress sets the number in law and increased the number to 435 in 1913. The Constitution set the number of representatives at 65 from 1787 until the first Census of 1790, when it was increased to 105 members. More about apportionment.
See related Census 2010 Apportionments.
Apportionment totals were calculated by a congressionally defined formula, in accordance with Title 2 of the U.S. Code, to divide among the states the 435 seats in the U.S. House of Representatives. The apportionment population consists of the resident population of the 50 states, plus the overseas military and federal civilian employees and their dependents living with them who could be allocated to a state. Each member of the House represents, on average, about 761,000 people based on Census 2020.
U.S. House Apportionment by State based on Census 2020 & Earlier Decennial Censuses Interactive Table
Click column header to sort; click again to sort other direction.
See usage notes below table. See related Related Interactive Tables
Use buttons below table select/filter rows & columns.
- Click Reset button to show all.
-1 denotes NA
- State Name
- 2020 Apportionment Population
- 2020 Resident Population
- 2020 Overseas Population
- 2010 Apportionment Population
- 2010 Resident Population
- 2010 Overseas Population
- 2010-20 App Population Change
- 2010-20 App Population %Change
- 2010-20 Res Population Change
- 2010-20 Res Population %Change
- Seats 2020
- Seats 2010
- Seats Change 2010-20
- Seats 2000
- Seats 1990
- Seats 1980
- Seats 1970
Using Apportionment GIS Project .. goto top
These operations require a Windows computer with Internet connection
Operations require ProximityOne User Group ID (join now)
1. Install the ProximityOne CV XE GIS
... not required if already installed.
... run the CV XE GIS installer
... take all defaults during installation
2. Download the Apportionment GIS Project fileset
... Expand Apportionment GIS Project to local folder c:\apportionment
3. Open the c:\apportionment\apportionment1.gis project
... after completing the above steps, click File>Open>Dialog
... open the file named c:\apportionment\apportionment1.gis
4. Done. The start-up view is shown at top of this section.
More About Apportionment .. goto top
The first decennial census was conducted in 1790 and has been taken every ten years as mandated by Article I, Section 2 of the U.S. Constitution. Since the first census, conducted by Thomas Jefferson, the decennial count has been the basis for our representative form of government as envisioned by our nation's Founding Fathers. In 1790, each member of the House of Representatives represented about 34,000 residents. Today, the House has more than quadrupled in size, and each member represents about 19 times as many constituents. In 2000, each member of the House of Representatives represented a population of about 647,000.
The apportionment population consists of the resident population of the 50 states, plus the overseas military and federal civilian employees and their dependents living with them who could be allocated to a state. The populations of the District of Columbia and Puerto Rico are excluded from the apportionment population because they do not have voting seats in the U. S. House of Representatives.
The apportionment totals are calculated by a congressionally defined formula in accordance with Title 2 of the U.S. Code.
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