The Census 2000 apportionment population was 281,424,177, as shown in

Table 1. The apportionment population

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. As required by the U.S. Supreme

Court ruling (Department of Commerce

v. House of Representatives, 525 U.S.

316, 119 S. Ct. 765 (1999)), the apportionment population counts do not

reflect the use of statistical sampling to

adjust for overcounting or undercounting

in the census.

This report, part of a series that analyzes

population and housing data collected by

Census 2000, examines trends in congressional apportionment and discusses

the apportionment population — what it

is, who is included, what method is used

to calculate it, and so forth.

Apportionment is a fundamental

reason for the census.

One of the fundamental reasons 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.

An apportionment has been made on the

basis of each decennial census from

1790 to 2000, except following the 

1920 census.

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 (see Table 1).

However, the apportionment based on the

1960 census, which took effect for the

congressional election in 1962, reverted

to 435 seats.

The average size of a congressional district based on the Census 2000 apportionment population will be 646,952, more

than triple the average district size of

193,167 based on the 1900 census

apportionment, and about 74,486 more

than the average size based on the 1990

census (572,466). Of the seven states

with one seat in Census 2000, the population of the largest — Montana — was

905,316, compared with an average size

of congressional district in the other 

U S C E N S U S B U R E A U

Helping You Make Informed Decisions

U.S.Department of Commerce

Economics and Statistics Administration

U.S. CENSUS BUREAU

Issued July 2001

C2KBR/01-7

Congressional Apportionment

Census 2000 Brief

By 

Karen M. Mills
2 U.S. Census Bureau

Table 1.

Apportionment Population Based on Census 2000 and Apportionment of

U.S. House of Representatives: 1900 to 2000

(For information on confidentiality protection, nonsampling error, and definitions, see www.census.gov/prod/cen2000/doc/pl94-171.pdf)

State

2000 apportionment population1 Number of representatives

Total

Resident

population

U.S.

population

overseas 2000 1990 1980 1970 1960 1950 1940 1930 19202 1910 1900

Apportionment

total . ........ 281,424,177 280,849,847 574,330 435 435 435 435 435 3437 435 435 435 3435 3391

Alabama . ......... 4,461,130 4,447,100 14,030 7 7 7 7 8 9 9 9 10 10 9

Alaska ............ 628,933 626,932 2,001 1 1 1 1 1 1 (X) (X) (X) (X) (X)

Arizona . . . . . . . . . . . 5,140,683 5,130,632 10,051 8 6 5 4 3 2 2 1 1 1 (X)

Arkansas .......... 2,679,733 2,673,400 6,333 4 4 4 4 4 6 7 7 7 7 7

California . . ........ 33,930,798 33,871,648 59,150 53 52 45 43 38 30 23 20 11 11 8

Colorado .......... 4,311,882 4,301,261 10,621 7 6 6 5 4 4 4 4 4 4 3

Connecticut ........ 3,409,535 3,405,565 3,970 5 6 6 6 6 6 6 6 5 5 5

Delaware .......... 785,068 783,600 1,468 1 1 1 1 1 1 1 1 1 1 1

Florida . . .......... 16,028,890 15,982,378 46,512 25 23 19 15 12 8 6 5 4 4 3

Georgia ........... 8,206,975 8,186,453 20,522 13 11 10 10 10 10 10 10 12 12 11

Hawaii . . . . . . . . . . . . 1,216,642 1,211,537 5,105 2 2 2 2 2 1 (X) (X) (X) (X) (X)

Idaho ............. 1,297,274 1,293,953 3,321 2 2 2 2 2 2 2 2 2 2 1

Illinois ............ 12,439,042 12,419,293 19,749 19 20 22 24 24 25 26 27 27 27 25

Indiana. . .......... 6,090,782 6,080,485 10,297 9 10 10 11 11 11 11 12 13 13 13

Iowa. . . . . . . . . . . . . . 2,931,923 2,926,324 5,599 5 5 6 6 7 8 8 9 11 11 11

Kansas ........... 2,693,824 2,688,418 5,406 4 4 5 5 5 6 6 7 8 8 8

Kentucky .......... 4,049,431 4,041,769 7,662 6 6 7 7 7 8 9 9 11 11 11

Louisiana .......... 4,480,271 4,468,976 11,295 7 7 8 8 8 8 8 8 8 8 7

Maine. ............ 1,277,731 1,274,923 2,808 2 2 2 2 2 3 3 3 4 4 4

Maryland . . ........ 5,307,886 5,296,486 11,400 8 8 8 8 8 7 6 6 6 6 6

Massachusetts...... 6,355,568 6,349,097 6,471 10 10 11 12 12 14 14 15 16 16 14

Michigan .......... 9,955,829 9,938,444 17,385 15 16 18 19 19 18 17 17 13 13 12

Minnesota ......... 4,925,670 4,919,479 6,191 8 8 8 8 8 9 9 9 10 10 9

Mississippi ......... 2,852,927 2,844,658 8,269 4 5 5 5 5 6 7 7 8 8 8

Missouri........... 5,606,260 5,595,211 11,049 9 9 9 10 10 11 13 13 16 16 16

Montana .......... 905,316 902,195 3,121 1 1 2 2 2 2 2 2 2 2 1

Nebraska .......... 1,715,369 1,711,263 4,106 3 3 3 3 3 4 4 5 6 6 6

Nevada . . . . . . . . . . . 2,002,032 1,998,257 3,775 3 2 2 1 1 1 1 1 1 1 1

New Hampshire..... 1,238,415 1,235,786 2,629 2 2 2 2 2 2 2 2 2 2 2

New Jersey ........ 8,424,354 8,414,350 10,004 13 13 14 15 15 14 14 14 12 12 10

New Mexico........ 1,823,821 1,819,046 4,775 3 3 3 2 2 2 2 1 1 1 (X)

New York . . . . . . . . . . 19,004,973 18,976,457 28,516 29 31 34 39 41 43 45 45 43 43 37

North Carolina . . .... 8,067,673 8,049,313 18,360 13 12 11 11 11 12 12 11 10 10 10

North Dakota . . . . . . . 643,756 642,200 1,556 1 1 1 1 2 2 2 2 3 3 2

Ohio. . . . . . . . . . . . . . 11,374,540 11,353,140 21,400 18 19 21 23 24 23 23 24 22 22 21

Oklahoma ......... 3,458,819 3,450,654 8,165 5 6 6 6 6 6 8 9 8 8 5

Oregon ........... 3,428,543 3,421,399 7,144 5 5 5 4 4 4 4 3 3 3 2

Pennsylvania . ...... 12,300,670 12,281,054 19,616 19 21 23 25 27 30 33 34 36 36 32

Rhode Island ....... 1,049,662 1,048,319 1,343 2 2 2 2 2 2 2 2 3 3 2

South Carolina. ..... 4,025,061 4,012,012 13,049 6 6 6 6 6 6 6 6 7 7 7

South Dakota. . . .... 756,874 754,844 2,030 1 1 1 2 2 2 2 2 3 3 2

Tennessee ......... 5,700,037 5,689,283 10,754 9 9 9 8 9 9 10 9 10 10 10

Texas . . . . . . . . . . . . . 20,903,994 20,851,820 52,174 32 30 27 24 23 22 21 21 18 18 16

Utah.............. 2,236,714 2,233,169 3,545 3 3 3 2 2 2 2 2 2 2 1

Vermont. . . . . . . . . . . 609,890 608,827 1,063 1 1 1 1 1 1 1 1 2 2 2

Virginia ........... 7,100,702 7,078,515 22,187 11 11 10 10 10 10 9 9 10 10 10

Washington ........ 5,908,684 5,894,121 14,563 9 9 8 7 7 7 6 6 5 5 3

West Virginia ....... 1,813,077 1,808,344 4,733 3 3 4 4 5 6 6 6 6 6 5

Wisconsin . . ....... 5,371,210 5,363,675 7,535 8 9 9 9 10 10 10 10 11 11 11

Wyoming . . . . . . . . . . 495,304 493,782 1,522 1 1 1 1 1 1 1 1 1 1 1

(X) Not applicable.

1

Includes the resident population for the 50 states, as ascertained by Census 2000 under Title 13, U.S. Code, and counts of overseas

U.S. military and federal civilian employees (and their dependents living with them) allocated to their home state, as reported by the employing federal agencies. The apportionment population does not include the resident or the overseas population of the District of Columbia. 2

No reapportionment was made based on the 1920 census.

3

Includes representatives assigned by Congress to newly admitted states after the apportionment act for that census: 1900, Oklahoma

(five representatives); 1910, Arizona and New Mexico (one representative each); and 1950, Alaska and Hawaii (one representative each).

Note: As required by the U.S. Supreme Court ruling (Department of Commerce v. House of Representatives, 525 U.S. 316, 119 S.

Ct. 765 (1999)), the Census 2000 apportionment population counts do not reflect the use of statistical sampling to adjust for overcounting

or undercounting.

Source: U.S. Census Bureau, Census 2000 and earlier censuses at www.census.gov/population/www/censusdata/apportionment.html;

and 1990 and earlier censuses also published in 1990 CPH-2-1, Population and Housing Unit Counts, United States, Table 3.
U.S. Census Bureau

3

State State No chState State 

Change fro

Censu

Note: Numtotals of U.Total U.S. re

Source: U.S. Census Bureau, Census 2000 and 1990 census at www.census.gov/population/www/censusdata/apportionment.html; 

and 1990 census also published in 1990 CPH-2-1, Population and Housing Unit Counts, United States, Table 3.

WEST

REGION MIDWEST

REGION

SOUTH

REGION

Figure 1.

Apportionment of the U.S. House of Representatives for the 108th Con

AK (For information on confidentiality protection, nonsampling error, and definitions, see www.census.gov/prod/

1

HI

2

WA

9

OR

5

CA

53

NV

3

AZ

8

ID

2

MT

1

WY

1

UT

3 CO

7

NM

3

ND

1

SD

1

NE

3

KS

4

MN

8

IA

5

MO

9

WI

8

IL

19

MI

15

IN

9

OH

18

OK

5

TX

32

AR

4

LA

7

WV

3

VA

11

NC

13

KY

6

TN

9

MS

4

AL

7

FL

 25

GA

13

SC

6

DE 1

MD 8

ME

2

NH

NY 2

29

PA

19

MA 

RI 

CT 5

NJ 13

VT

1
43 states of 646,259. Wyoming,

also with one seat in Census 2000,

had the smallest district size, with

495,304. 

Twelve seats in the U.S. House

of Representatives will shift

from one state to another.

As a result of the apportionment

based on Census 2000, 12 seats in

the U.S. House of Representatives

will shift among 18 states. Eight

states will have more representatives in the 108th Congress, which

convenes in January 2003, and ten

states will have fewer representatives (see Figure 1 and Table 2). 

Of the eight states gaining seats,

four — Arizona, Florida, Georgia,

and Texas — will each gain two

seats. The other four — California,

Colorado, Nevada, and North

Carolina — will each gain one seat.

Of the ten states losing seats, two

— New York and Pennsylvania —

will each lose two seats. The other

eight — Connecticut, Illinois,

Indiana, Michigan, Mississippi,

Ohio, Oklahoma, and Wisconsin —

will each lose one seat.

The 1990 census

apportionment shifted 19 seats.

Following the 1990 census, reapportionment shifted 19 seats

among 21 states (see Table 2). The

largest gains were in California

(seven seats), Florida (four seats),

and Texas (three seats). Five states

gained one seat each: Arizona,

Georgia, North Carolina, Virginia,

and Washington.

The largest losses in seats after the

1990 census apportionment were in

New York (three fewer seats); and in

Illinois, Michigan, Ohio, and

Pennsylvania (two fewer seats

each). Eight states lost one seat

each: Iowa, Kansas, Kentucky,

Louisiana, Massachusetts, Montana,

New Jersey, and West Virginia.

Shifts in congressional

representation reflect

regional trends in population.

The regional patterns of change in

congressional representation

between 1990 and 2000 reflect the

Nation’s continuing shift in population from the Northeast and

Midwest to the South and West. 

Based on the Census 2000 apportionment, the net increase of five

seats in the South reflected a gain

of seven seats in four states and a

loss of two seats, one each in

Mississippi and Oklahoma (see

Table 3). The West gained five

seats and lost none; the Northeast

and Midwest each lost five seats

and gained none.

Based on the 1990 census apportionment, the net increase of seven

seats in the South reflected a gain

of ten seats in five states and a

loss of three seats, one each in

Kentucky, Louisiana, and West

Virginia. The net increase of eight

seats in the West reflected a gain

of nine seats in three states and a

loss of one seat in Montana. The

Northeast lost seven seats and

gained none; the Midwest lost

eight seats and gained none.

Figure 2 shows the percentage

distribution of House seats or

4 U.S. Census Bureau

Table 2.

Change in the Number of U.S. Representatives by State:

1990 and 2000

(For information on confidentiality protection, nonsampling error, and definitions, see

www.census.gov/prod/cen2000/doc/pl94-171.pdf)

State Seats

gained State Seatslost

BASED ON THE 1990 CENSUS

Total gain in 8 states . . . . . . . . . . 19 Total loss in 13 states . . . . . . 19

California. . . . . . . . . . . . . . . . . . . . . . . . 7 New York . . . . . . . . . . . . . . . . . . . . . 3

Florida . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Illinois . . . . . . . . . . . . . . . . . . . . . . . . 2

Texas . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Michigan . . . . . . . . . . . . . . . . . . . . . 2

Arizona . . . . . . . . . . . . . . . . . . . . . . . . . 1 Ohio . . . . . . . . . . . . . . . . . . . . . . . . . 2

Georgia . . . . . . . . . . . . . . . . . . . . . . . . . 1 Pennsylvania. . . . . . . . . . . . . . . . . . 2

North Carolina . . . . . . . . . . . . . . . . . . . 1 Iowa . . . . . . . . . . . . . . . . . . . . . . . . . 1

Virginia. . . . . . . . . . . . . . . . . . . . . . . . . . 1 Kansas. . . . . . . . . . . . . . . . . . . . . . . 1

Washington. . . . . . . . . . . . . . . . . . . . . . 1 Kentucky . . . . . . . . . . . . . . . . . . . . . 1

Louisiana . . . . . . . . . . . . . . . . . . . . . 1

Massachusetts . . . . . . . . . . . . . . . . 1

Montana. . . . . . . . . . . . . . . . . . . . . . 1

New Jersey . . . . . . . . . . . . . . . . . . . 1

West Virginia. . . . . . . . . . . . . . . . . . 1

BASED ON CENSUS 2000

Total gain in 8 states . . . . . . . . . . 12 Total loss in 10 states . . . . . . 12

Arizona . . . . . . . . . . . . . . . . . . . . . . . . . 2 New York . . . . . . . . . . . . . . . . . . . . . 2

Florida . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Pennsylvania. . . . . . . . . . . . . . . . . . 2

Georgia . . . . . . . . . . . . . . . . . . . . . . . . . 2 Connecticut . . . . . . . . . . . . . . . . . . . 1

Texas . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Illinois . . . . . . . . . . . . . . . . . . . . . . . . 1

California. . . . . . . . . . . . . . . . . . . . . . . . 1 Indiana . . . . . . . . . . . . . . . . . . . . . . . 1

Colorado . . . . . . . . . . . . . . . . . . . . . . . . 1 Michigan . . . . . . . . . . . . . . . . . . . . . 1

Nevada . . . . . . . . . . . . . . . . . . . . . . . . . 1 Mississippi . . . . . . . . . . . . . . . . . . . . 1

North Carolina . . . . . . . . . . . . . . . . . . . 1 Ohio . . . . . . . . . . . . . . . . . . . . . . . . . 1

Oklahoma . . . . . . . . . . . . . . . . . . . . 1

Wisconsin . . . . . . . . . . . . . . . . . . . . 1

Source: U.S. Census Bureau, Census 2000 and 1990 census at www.census.gov/

population/www/censusdata/apportionment.html; and 1990 census also published in 1990

CPH-2-1, Population and Housing Unit Counts, United States, Table 3.
U.S. Census Bureau 5

memberships by region for each

census in the 20th century. The

West gradually increased its share

of House seats in each decade of

the last century, so that its 23-percent share in 2000 was more than

four times its 5-percent share in

1900. 

During the same time, the South’s

share of House seats, after a small

initial fall between 1900 and 1910,

held steady at 31 percent for

seven decades, until rising to 

35 percent by 2000. The South

continued to hold the largest share

of House seats of any of the four

regions in 2000, as it has since

1940. 

Meanwhile, the Midwest, which

accounted for the largest regional

share of House seats from 1900 to

1920, showed a gradual decline in

its share to 23 percent in 2000,

the same as the West. 

After holding 28 percent of the

House seats from 1900 to 1940,

the Northeast saw a drop to 

19 percent by 2000, the smallest

share of House seats of any of the

four regions.

The Congress decides the

method to calculate the

apportionment.

Several apportionment methods

have been used since the first census in 1790. The apportionment

for Census 2000 was calculated

using the method of equal proportions, in accordance with the provisions of Title 2, U.S. Code. This

method has been used in every

census since the 1940 census.

First, each state is assigned one

congressional seat, as provided by

the Constitution. Then the apportionment formula allocates the

remaining 385 congressional seats

Table 3.

Change in the Number of U.S. Representatives by Region:

1990 and 2000

(For information on confidentiality protection, nonsampling error, and definitions, see

www.census.gov/prod/cen2000/doc/pl94-171.pdf)

Region

Seats changed

based on the

1990 census

Seats changed

based on

Census 2000

Northeast (net) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -7 -5

Gained . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - -

Lost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5

Midwest (net). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -8 -5

Gained . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - -

Lost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5

South (net) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5

Gained . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7

Lost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2

West (net) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5

Gained . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5

Lost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 -

- Represents zero.

Source: U.S. Census Bureau, Census 2000 and 1990 census at www.census.gov/

population/www/censusdata/apportionment.html; and 1990 census also published in 1990

CPH-2-1, Population and Housing Unit Counts, United States, Table 3.

Figure 2.

Percentage Distribution of Seats in the U.S. House 

of Representatives by Region: 1900 to 2000

Source: U.S. Census Bureau, Census 2000 and earlier censuses at www.census.gov/population/www/

censusdata/apportionment.html; and 1990 and earlier censuses also published in 1990 CPH-2-1, 

Population and Housing Unit Counts, United States, Table 3.

28 28 28 28 28 26 25 24 22 20 19

35 33 33 31 30 30 29 28

26 24 23

32 31 31 31 31 31 31 31

33 34 35

5 8 8 10 11 14 16 17 20 21 23

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

West

Northeast 

Midwest 

South 

(For information on confidentiality protection, nonsampling error, and 

definitions, see www.census.gov/prod/cen2000/doc/pl94-171.pdf)
one at a time among the 50 states

until all 435 seats are assigned. 

The goal of apportionment is to

produce the most equitable distribution of congressional seats

among the states. The method of

equal proportions attains this by

minimizing the percentage

differences in the size of the congressional districts.

ADDITIONAL TOPICS ON

CONGRESSIONAL

APPORTIONMENT

When are the apportionment

population counts given to the

President? To the Congress?

To the states? 

To the President. Title 13, U.S. Code,

requires that the apportionment

population counts for each state be

delivered to the President within 

9 months of Census Day, which was

April 1, 2000. The Census 2000

counts were delivered to the

President on December 28, 2000.

To the Congress. According to Title

2, U.S. Code, within 1 week of the

opening of the next session of the

Congress in the new year, the

President must report to the Clerk

of the U.S. House of Representatives

the apportionment population

counts for each state and the number of representatives to which

each state is entitled. 

To the States. Also according to

Title 2, U.S. Code, within 15 days of

receiving the apportionment population counts from the President,

the Clerk of the House must inform

each state governor of the number

of representatives to which each

state is entitled. 

Were undocumented residents

(aliens) in the 50 states

included in the Census 2000

apportionment population

counts? 

Yes, all people (citizens and noncitizens) with a usual residence in one

of the 50 states were included in

Census 2000 and thus in the apportionment counts. 

Were children under 18 years

old included in the Census

2000 apportionment

population counts even

though they cannot vote? 

Yes, being old enough to vote,

being registered to vote, or voting

are not requirements for inclusion

in the apportionment counts. 

Did the Census 2000

apportionment population

counts also include any

Americans overseas? 

Yes, as for the 1990 census, the

Census 2000 apportionment counts

included those overseas federal

employees (military and civilian)

and their dependents living with

them that could be assigned to a

home state. These data were provided to the Census Bureau by the

employing federal departments and

agencies from their administrative

records. Private U.S. citizens living

abroad who were not affiliated with

the federal government (either as

employees or their dependents)

were not included in the overseas

counts, which are used solely for

reapportioning seats in the U.S.

House of Representatives, not for

redistricting (see question below). 

What is the difference

between apportionment and

redistricting? 

Population data from the decennial

census provide the basis for both

apportioning seats in the House of

Representatives among the states

and for redistricting this and other

legislative bodies.

Apportionment is the process of

determining the number of representatives to which each state is

entitled in the U.S. House of

Representatives based on the

decennial census. By law, the apportionment results (the apportionment

population of each state) must be

submitted to the President within 

9 months of the census date.

Redistricting is the process of revising the geographic boundaries of

areas from which people elect representatives to the U.S. House of

Representatives, a state legislature,

a county or city council, a school

board, and so forth. By law, redistricting data must be submitted to

the states within 1 year of the census date. The Census Bureau

released the redistricting population

data at the census block level on a

state-by-state basis during March

2001.

FOR MORE INFORMATION 

Census 2000 data are available on

the Internet via factfinder.census.gov

and for purchase on CD-ROM and

later on DVD. For more information

on apportionment for both Census

2000 and the 1990 census, visit the

U.S. Census Bureau’s Internet site at

www.census.gov/

population/www/censusdata/

apportionment.html. 

Information on other population

and housing topics is presented in

the Census 2000 Brief series, located on the U.S. Census Bureau’s Web

site at www.census.gov/

population/www/cen2000/briefs.html.

This series presents information

about race, Hispanic origin, age,

sex, household type, housing

tenure, and other social, economic,

and housing characteristics.

For more information about Census

2000, including data products, call

our Customer Services Center at

301-763-INFO (4636) or e-mail 

webmaster@census.gov.

6 U.S. Census Bureau

U.S. Department of Commerce

Economics and Statistics Administration

U.S. CENSUS BUREAU

Washington, DC 20233

OFFICIAL BUSINESS

Penalty for Private Use $300

FIRST-CLASS MAIL

POSTAGE & FEES PAID

U.S. Census Bureau

Permit No. G-58