Article

Congressional Apportionment

The average size of a congressional district will rise.
Twelve seats will shift from one state to another.
Shifts in congressional representation reflect regional trends in population
For more information

The Constitutional basis for conducting the decennial census of population is to reapportion the U.S. House of Representatives. Apportionment is the process of dividing the 435 memberships, or seats, in the U.S. House of Representatives among the 50 states. With the exception of the 1920 Census, an apportionment has been made by the Congress on the basis of each decennial census from 1790 to 2010.

The apportionment population for 2010 consists of the resident population of the 50 states plus overseas federal employees (military and civilian) and their dependents living with them, who were included in their home states. The population of the District of Columbia is excluded from the apportionment population because it does not have any voting seats in the U.S. House of Representatives. The 2010 Census apportionment population was 309,183,463.

The average size of a congressional district will rise.

The number of representatives or seats in the U.S. House of Representatives has remained constant at 435 since 1911, except for a temporary increase to 437 at the time of admission of Alaska and Hawaii as states in 1959. However, the apportionment based on the 1960 Census, which took effect for the election in 1962, reverted to 435 seats.

The average size of a congressional district based on the 2010 Census apportionment population will be 710,767, more than triple the average district size 100 years ago, and 63,815 more than the average size based on the 2000 Census. Based on the 2010 Census apportionment, the state with the largest average district size will be Montana and the state with the smallest average district size will be Rhode Island.

State	2010 Apportionment Population	Number of Representatives
State	2010 Apportionment Population	2010	2000	1910

Total	309,183,463	435	435	435
Alabama	4,802,982	7	7	10
Alaska	721,523	1	1	0
Arizona	6,412,700	9	8	1
Arkansas	2,926,229	4	4	7
California	37,341,989	53	53	11
Colorado	5,044,930	7	7	4
Connecticut	3,581,628	5	5	5
Delaware	900,877	1	1	1
Florida	18,900,773	27	25	4

Georgia	9,727,566	14	13	12
Hawaii	1,366,862	2	2	0
Idaho	1,573,499	2	2	2
Illinois	12,864,380	18	19	27
Indiana	6,501,582	9	9	13
Iowa	3,053,787	4	5	11
Kansas	2,863,813	4	4	8
Kentucky	4,350,606	6	6	11
Louisiana	4,553,962	6	7	8
Maine	1,333,074	2	2	4

Maryland	5,789,929	8	8	6
Massachusetts	6,559,644	9	10	16
Michigan	9,911,626	14	15	13
Minnesota	5,314,879	8	8	10
Mississippi	2,978,240	4	4	8
Missouri	6,011,478	8	9	16
Montana	994,416	1	1	2
Nebraska	1,831,825	3	3	6
Nevada	2,709,432	4	3	1
New Hampshire	1,321,445	2	2	2
New Jersey	8,807,501	12	13	12
New Mexico	2,067,273	3	3	1
New York	19,421,055	13	13	10
North Carolina	9,565,781	1	1	3
North Dakota	675,905	15	18	22
Ohio	11,568,495	16	18	22
Oklahoma	3,764,882	5	5	8
Oregon	3,848,606	5	5	8
Pennsylvania	12,734,905	18	19	36
Rhode Island	1,055,247	2	2	3

South Carolina	4,645,975	7	6	7
South Dakota	819,761	1	1	3
Tennessee	6,375,431	9	9	10
Texas	25,268,418	36	32	18
Utah	2,770,765	4	3	2
Vermont	630,337	1	1	2
Virginia	8,037,736	11	11	10
Washington	6,753,369	10	9	5
West Virginia	1,859,815	3	3	6
Wisconsin	5,698,230	8	8	11
Wyoming	568,300	1	1	1

Table 1: Apportionment Based on the 2010 Census and Apportionment of the U.S. House of Representatives 2010, 2000, and 1910

Twelve seats in the U.S. House of Representatives will shift from one state to another.

As a result of the apportionment based on the 2010 Census, 12 seats in the U.S. House of Representatives will shift among 18 states. Eight states will have more representatives in the 113th Congress, which convened in January 2013, and ten states will have fewer representative.

Among the eight states gaining seats, Texas will gain four seats and Florida will gain two seats. The other six states (Arizona, Georgia, Nevada, South Carolina, Utah, and Washington) will each gain one seat. Of the ten states losing seats, two states, New York and Ohio, will each lose two seats. The other eight states (Illinois, Iowa, Louisiana, Massachusetts, Michigan, Missouri, New Jersey, and Pennsylvania) will each lose one seat.

Change in the Number of U.S. Representatives by State - 2010
State	Gain	State	Loss
Total	12	Total	12
Texas	4	New York	2
Florida	2	Ohio	2
Arizona	1	Illinois	1
Georgia	1	Iowa	1
Nevadaa	1	Louisiana	1
South Carolina	1	Massachusetts	1
Utah	1	Michigan	1
Washington	1	Missouri	1
		New Jersey	1
		Pennsylvania	1

Table 2: Change in the Number of U.S. Representatives by state 2010

Shifts in congressional representation reflect regional trends in population.

The regional patterns of change in congressional representation between 2000 and 2010 reflect the nation's continuing shift in population from the Northeast and Midwest to the South and West.

Based on the 2010 Census apportionment, the net increase of seven seats in the South reflected a gain of eight seats across four states and a loss of one seat. The West gained four seats and lost none. The Northeast lost five seats and gained none. The Midwest lost six seats and gained none.

Figure 1: Regional shifts in congressional representation based on the 2010 census

For more information

For more information on apportionment for both the 2010 and 2000 censuses, visit the U.S. Census Bureau's Internet site. Other data from the 2010 Census are also available.

Adapted from Kristin D. Burnett, U.S. Census Bureau, Congressional Apportionment in 2010 Census Briefs.


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