United States congressional apportionment

Allocation of seats by state, as percentage of overall number of representatives in the House, 1789–2020 census

United States congressional apportionmentis the processby which seats in theUnited States House of Representativesare distributed among the 50statesaccording to the most recent decennialcensusmandated by theUnited States Constitution.After each state is assigned one seat in the House, most states are thenapportioneda number of additional seats which roughly corresponds to its share of the aggregate population of the 50 states.Every state is constitutionally guaranteed at least one seat in the House and two seats in theSenate,regardless of population.

The number of voting seats in the House of Representatives has been 435 since 1913, capped at that number by theReapportionment Act of 1929—except for a temporary (1959–1962) increase to 437 whenAlaskaandHawaiiwereadmitted into the Union.TheHuntington–Hill method of equal proportionshas been used to distribute the seats among the states since the1940 censusreapportionment.Federal law requires theClerk of the United States House of Representativesto notify each state government of the number of seats apportioned to the state no later than January 25 of the year immediately following each decennialcensus.

The size of a state's total congressional delegation (which in addition to representative(s) includes 2senatorsfor each state) also determines the size of its representation in theU.S. Electoral College,whichelects the U.S. president.

Constitutional context

Article One,Section 2, Clause 3 of theUnited States Constitutioninitially provided:

Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed,three fifths of all other Persons. The Number of Representatives shall not exceed one for every thirty Thousand, but each State shall have at least one Representative;…

The phrase "all other persons" refers to slaves, a word not used in the Constitution until theThirteenth Amendment.

Following the end of theCivil War,the first of those provisions was superseded by Section 2 of theFourteenth Amendment:

Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State, excluding Indians not taxed.But when the right to vote at any election for the choice of electors for President and Vice-President of the United States, Representatives in Congress, the Executive and Judicial officers of a State, or the members of the Legislature thereof, is denied to any of the male inhabitants of such State, being twenty-one years of age, and citizens of the United States, or in any way abridged, except for participation in rebellion, or other crime, the basis of representation therein shall be reduced in the proportion which the number of such male citizens shall bear to the whole number of male citizens twenty-one years of age in such State.

The phrase "counting the whole number of persons in each State" has traditionally been understood to include non-citizens for purposes of apportionment.

Reapportionment

Reapportionments normally occur following each decennial census, though the law that governs the total number of representatives and the method of apportionment to be carried into force at that time are enacted prior to the census.

The decennial apportionment also determines the size of each state's representation in theU.S. Electoral College.UnderArticle II, Section 1, Clause 2of the U.S. Constitution, the number of electors of any state equals the size of its total congressional delegation (House and Senate seats).

Federal law requires theClerk of the House of Representativesto notify each state government no later than January 25 of the year immediately following the census of the number of seats to which it is entitled. Whether or not the number of seats has changed, the state determines the boundaries ofcongressional districts—geographical areas within the state of approximately equal population—in a process calledredistricting.

Because the deadline for the House Clerk to report the results does not occur until the following January, and the states need sufficient time to perform the redistricting, the decennial census does not affect the elections that are held during that same year. For example, the electoral college apportionment and congressional races during the 2020 presidential election year were still based on the 2010 census results; all of the newly redrawn districts based on the 2020 census did not finally come into force until the 2022 midterm election winners were inaugurated in January 2023.

Number of members

The U.S. population has increased more rapidly than the membership of the House of Representatives.

The size of the U.S. House of Representatives refers to the total number of congressional districts (or seats) into which the land area of the United States proper has been divided. The number of voting representatives is currentlyset at 435.There are an additional fivedelegates to the House of Representatives.They represent theDistrict of Columbiaand the territories ofAmerican Samoa,Guam,theNorthern Mariana Islands,which first elected a representative in 2008,and theU.S. Virgin Islands.Puerto Ricoalso elects aresident commissionerevery four years.

Controversy and history

Since 1789, when theUnited States Congressfirst convened under the Constitution, the number of citizens per congressional district has risen from an average of 33,000 in 1790 to over 700,000 as of 2018.Prior to the 20th century, the number of representatives increased every decade as more states joined the union, and the population increased.

Representation in the House, historical

Starting yearY	Source	Avg. constituents per member
1793	1790 census	34,436
1803	1800 census	34,609
1813	1810 census	36,377
1823	1820 census	42,124
1833	1830 census	49,712
1843	1840 census	71,338
1853	1850 census	93,020
1863	1860 census	122,614
1873	1870 census	130,533
1883	1880 census	151,912
1893	1890 census	173,901
1903	1900 census	193,167
1913	1910 census	210,583
1923	1920 census	243,728
1933	1930 census	280,675
1943	1940 census	301,164
1953	1950 census	334,587
1963	1960 census	410,481
1973	1970 census	469,088
1983	1980 census	510,818
1993	1990 census	571,477
2003	2000 census	646,946
2013	2010 census	709,760
2023	2020 census	761,169
YElections are held the preceding year

The ideal number of members has been a contentious issue since the country's founding.George Washingtonagreed that the original representation proposed during theConstitutional Convention(one representative for every 40,000) was inadequate and supported an alteration to reduce that number to 30,000.This was the only time that Washington pronounced an opinion on any of the actual issues debated during the entire convention.Five years later, Washington was so insistent on having no more than 30,000 constituents per representative that he exercised the first presidentialvetoin history ona billwhich allowed half states to go over the quota.

InFederalist No. 55,James Madisonargued that the size of the House of Representatives has to balance the ability of the body to legislate with the need for legislators to have a relationship close enough to the people to understand their local circumstances, that such representatives' social class be low enough to sympathize with the feelings of the mass of the people, and that their power be diluted enough to limit their abuse of the public trust and interests.

... first, that so small a number of representatives will be an unsafe depositary of the public interests; secondly, that they will not possess a proper knowledge of the local circumstances of their numerous constituents; thirdly, that they will be taken from that class of citizens which will sympathize least with the feelings of the mass of the people, and be most likely to aim at a permanent elevation of the few on the depression of the many;...

Madison also addressed Anti-Federalist claims that the representation would be inadequate, arguing that the major inadequacies are of minimal inconvenience since these will be cured rather quickly by virtue of decennial reapportionment. He noted, however,

I take for granted here what I shall, in answering the fourth objection, hereinafter show, that the number of representatives will be augmented from time to time in the manner provided by the Constitution. On a contrary supposition, I should admit the objection to have very great weight indeed.

Madison argued against the assumption that more is better:

Sixty or seventy men may be more properly trusted with a given degree of power than six or seven. But it does not follow that six or seven hundred would be proportionally a better depositary. And if we carry on the supposition to six or seven thousand, the whole reasoning ought to be reversed.... In all very numerous assemblies, of whatever character composed, passion never fails to wrest the scepter from reason.

Global comparison and disparities

When talking about the populations within California's reapportionedHouse districtsin 1951, a report fromDuke Universityfound that "[there] is not an excessive disparity in district populations, but [the populations and disparities are] perhaps larger than necessary."If the House had a similar ratio of representatives to constituents as it did after the1930 United States census,it would currently have 1,156 members (still just the second largest lower house, afterChina).

The United States has unusually large constituencies compared to otherOECDcountries,thethird largestin the world. However, most of this is caused by the United States's large population (the fourth-largest in the world) (seecube root law).

Membership cap

TheApportionment Act of 1911(Public Law 62-5) raised the membership of the U.S. House to 433 and provided for an apportionment. It also provided for additional seats upon the admissions ofArizonaandNew Mexicoas states, increasing the number to 435 in 1912.

In 1921, Congress failed to reapportion the House membership as required by the United States Constitution. This failure to reapportion may have been politically motivated, as thenewly elected Republican majoritymay have feared the effect such a reapportionment would have on their future electoral prospects.A reapportionment in 1921 in the traditional fashion would have increased the size of the House to 483 seats,but many members would have lost their seats due to the population shifts, and the House chamber did not have adequate seats for 483 members. By 1929, no reapportionment had been made since 1911, and there was vast representational inequity, measured by the average district size. By 1929 some states had districts twice as large as others due to population growth and demographic shift.

In 1929 Congress (with Republican control of both houses of Congress and the presidency) passed theReapportionment Act of 1929which capped the size of the House at 435 and established a permanent method for apportioning a constant 435 seats. This cap has remained unchanged since then, except for a temporary increase to 437 members upon the 1959 admission ofAlaskaandHawaiiinto the Union.

Two states,WyomingandVermont,have populations smaller than the average for a single district, although neither state has fewer people than the least populous congressional districts.

Proposed expansion

Among theBill of Rightsamendments to the United States Constitution proposed by Congress in 1789, was oneaddressing the number of seats in the House.It attempted to set a pattern for growth of the House along with the population, but has not been ratified.

After the firstenumerationrequired by the first article of the Constitution, there shall be one Representative for every thirty thousand, until the number shall amount to one hundred, after which the proportion shall be so regulated by Congress, that there shall be not less than one hundred Representatives, nor less than one Representative for every forty thousand persons, until the number of Representatives shall amount to two hundred; after which the proportion shall be so regulated by Congress, that there shall not be less than two hundred Representatives, nor more than one Representative for every fifty thousand persons.

Taken at face-value, with the nation's population reaching approximately 308.7 million according to the2010 census,the proposed amendment would have called for an up-to 6,000-member House.However, in the context of its original construction, the amendment may have instead outlined an iterative procedure for apportionment following asquare root rulerelative to the population (e.g.${\textstyle Representatives\approx {\sqrt {10000+Population/100}}-100}$) that would still have called for a more than 1,600-member House following the same 2010 census.

One proposal to alleviate the current constituency disparities and the high average number of constituents in many states' congressional districts is the "Wyoming rule."Operating similar to New Zealand'smethod of allocationfor proportional representation, it would give the least populous state (which has beenWyoming since 1990) one representative and then create districts in other states with the same population.

Another proposed expansion rule, thecube root rule,calls for the membership of the legislature to be based on thecube root(rounded up) of the U.S. population at the last census. For example, such a rule would call for 692 members of the House based on the 2020 United States census. An additional House member would be added each time thenationalpopulationexceedsthe next cube; in this case, the next House member would be added when the census population reached 331,373,889, and the one after that at 332,812,558. A variation would split the representation between the House and the Senate, e.g. 592 members in the House (692 − 100 senators).

On May 21, 2001, Rep.Alcee Hastingssent adear colleague letterpointing out that U.S. expansion of its legislature had not kept pace with other countries.

In 2007, during the110th Congress,Representative Tom Davisintroduced a bill in the House of Representatives that would add two seats to the House, one for Utah and one for theDistrict of Columbia.It was passed by the House, but was tripped up by procedural hurdles in the Senate and withdrawn from consideration. An identical bill was reintroduced during the110th Congress.In February 2009 the Senate adopted the measure 61–37. In April 2010, however, House leaders decided to shelve the proposal.

Two provisions of Section 102, subsection (d) in theWashington, D.C., Admission Actby delegateEleanor Holmes Nortonand its same-titled Senate companion by Sen.Tom Carper,both introduced in 2021 and again in 2023 during the117thand118th Congresses,seek to amend Section 22(a) of the Reapportionment Act by adding one to the permanent House membership for a total of 436 representatives as the state of Washington, Douglass Commonwealth (i.e., Washington, D.C.) would have been entitled to an at-large district.Holmes Norton's bill previously passed the House during the116th Congressbut not the Senate.

Apportionment methods

Apportionment in the House of the US population, 2010–2019

State	Population percent		House percent
	2019	2010	2019	2010
California	12.06%	12.09%	11.95%	12.18%
Texas	8.85%	8.16%	8.74%	8.28%
Florida	6.56%	6.10%	6.44%	6.21%
New York	5.94%	6.29%	5.98%	6.21%
Pennsylvania	3.91%	4.12%	3.91%	4.14%
Illinois	3.87%	4.16%	3.91%	4.14%
Ohio	3.57%	3.74%	3.68%	3.68%
Georgia	3.24%	3.14%	3.22%	3.22%
North Carolina	3.20%	3.09%	3.22%	2.99%
Michigan	3.05%	3.21%	2.99%	3.22%
New Jersey	2.71%	2.85%	2.76%	2.76%
Virginia	2.61%	2.60%	2.53%	2.53%
Washington	2.32%	2.18%	2.30%	2.30%
Arizona	2.22%	2.07%	2.30%	2.07%
Massachusetts	2.10%	2.12%	2.07%	2.07%
Tennessee	2.09%	2.06%	2.07%	2.07%
Indiana	2.06%	2.10%	2.07%	2.07%
Missouri	1.87%	1.94%	1.84%	1.84%
Maryland	1.85%	1.87%	1.84%	1.84%
Wisconsin	1.78%	1.85%	1.84%	1.84%
Colorado	1.76%	1.63%	1.84%	1.61%
Minnesota	1.72%	1.72%	1.61%	1.84%
South Carolina	1.57%	1.50%	1.61%	1.61%
Alabama	1.50%	1.55%	1.61%	1.61%
Louisiana	1.42%	1.47%	1.38%	1.38%
Kentucky	1.36%	1.41%	1.38%	1.38%
Oregon	1.29%	1.24%	1.38%	1.15%
Oklahoma	1.21%	1.22%	1.15%	1.15%
Connecticut	1.09%	1.16%	1.15%	1.15%
Utah	0.98%	0.90%	0.92%	0.92%
Iowa	0.96%	0.99%	0.92%	0.92%
Nevada	0.94%	0.88%	0.92%	0.92%
Arkansas	0.92%	0.95%	0.92%	0.92%
Mississippi	0.91%	0.96%	0.92%	0.92%
Kansas	0.89%	0.93%	0.92%	0.92%
New Mexico	0.64%	0.67%	0.69%	0.69%
Nebraska	0.59%	0.59%	0.69%	0.69%
West Virginia	0.55%	0.60%	0.46%	0.69%
Idaho	0.55%	0.51%	0.46%	0.46%
Hawaii	0.43%	0.44%	0.46%	0.46%
New Hampshire	0.42%	0.43%	0.46%	0.46%
Maine	0.41%	0.43%	0.46%	0.46%
Montana	0.33%	0.32%	0.46%	0.23%
Rhode Island	0.32%	0.34%	0.23%	0.46%
Delaware	0.30%	0.29%	0.23%	0.23%
South Dakota	0.27%	0.26%	0.23%	0.23%
North Dakota	0.23%	0.22%	0.23%	0.23%
Alaska	0.22%	0.23%	0.23%	0.23%
Vermont	0.19%	0.20%	0.23%	0.23%
Wyoming	0.18%	0.18%	0.23%	0.23%

Apart from the requirement that each state is to be entitled to at least one representative in the House of Representatives, the number of representatives in each state is in principle to be proportional to its population. Since the adoption of theConstitution,five distinct apportionment methods have been used.

Partisan control of congressional redistricting after the 2020 elections, with the number of U.S. House seats each state will receive.

Democratic control

Republican control

Split or bipartisan control

Independent redistricting commission

No redistricting necessary

The first apportionment was contained inArt. I, § 2, cl. 3 of the Constitution.After the first census in 1790, Congress passed theApportionment Act of 1792and adopted theJefferson methodto apportion U.S. representatives to the states based on population.The Jefferson method required fractionalremaindersto be discarded when calculating each state's total number of U.S. representatives and was used until the 1830 census.TheWebster method,proposed in 1832 byDaniel Websterand adopted for the 1840 census, allocated an additional representative to states with a fractional remainder greater than 0.5.

From 1850 to 1900, the situation was substantially less clear. Congress passed a law in 1850 declaring future apportionment would be done withHamilton's method.However, Congress continued to pass ad hoc apportionment bills from 1850 through 1900 which overruling the procedure laid out, particularly in the 1860 Census (complicated by theCivil War), where no real apportionment method was used. Apart from 1860, Congress deliberately chose to set the size of the House at a level where Hamilton and Webster's methods gave the same apportionment.This unofficial adoption ofWebster's methodwas driven by the discovery of theAlabama paradox,which created an uproar in the House.TheApportionment Act of 1911,in addition to setting the number of U.S. representatives at 435, returned to the Webster method, which was used following the 1910 and 1930 censuses (no reapportionment was done after the 1920 census). The current method, known as theHuntington–Hill methodor method of equal proportions, was adopted in 1941 for reapportionment based on the 1940 census and beyond.The revised method was necessary in the context of the cap on the number of representatives set in theReapportionment Act of 1929.

Method of equal proportions

Further information:Huntington–Hill method

The apportionment method currently used is the method of equal proportions, which minimizes thepercentage differencesin the number of people per representative among the different states.The resulting apportionment is optimal in the sense that any additional transfer of a seat from one state to another would result in larger percentage differences.

In this method, as a first step, each of the 50 states is given its one guaranteed seat in the House of Representatives, leaving 385 seats to assign. The remaining seats are allocated one at a time, to the state with the highest priority number. Thus, the 51st seat would go to the most populous state (currently California). The priority number is determined by the ratio of the state population to thegeometric meanof the number of seats it currently holds in the assignment process,n(initially 1), and the number of seats itwouldholdifthe seat were assigned to it,n+1. Symbolically, the priority numberA_nis

$A_{n}={\frac {P}{\sqrt {n(n+1)}}}$

wherePis the population of the state, andnis the number of seats it currently holds before the possible allocation of the next seat. An equivalent, recursive definition is

$A_{m+1}={\sqrt {\frac {m}{m+2}}}\ A_{m}$

$A_{n}={\sqrt {\frac {n-1}{n+1}}}\ A_{n-1}$

wherenisstillthe number of seats the state hasbeforeallocation of the next (in other words, for themth allocation,n=m-1).

Consider the reapportionment following the 2010 U.S. census: beginning with all states initially being allocated one seat, the largest value ofA₁corresponds to the largest state, California, which is allocated seat 51. After being allocated its 2nd seat, its priority value decreases to itsA₂value, which is reordered to a position back in line. The 52nd seat goes to Texas, the 2nd largest state, because itsA₁priority value is larger than theA_nof any other state. However, the 53rd seat goes back to California because itsA₂priority value is larger than theA_nof any other state. The 54th seat goes to New York because itsA₁priority value is larger than theA_nof any other state at this point. This process continues until all remaining seats are assigned. Each time a state is assigned a seat,nis incremented by 1, causing its priority value to be reduced and reordered among the states, whereupon another state normally rises to the top of the list.

The 2010 census ranking of priority valuesshows the order in which seats 51–435 were apportioned after the 2010 census, with additional listings for the next five priorities.Minnesotawas allocated the final (435th) seat.North Carolinamissed its 14th seat by 15,754 residents as the 436th seat to be allocated; ten years earlier it had gained its 13th seat as the 435th seat to be allocated based on the 2000 census.

The 2020 census ranking of priority valuesshows the order in which seats 51–435 were apportioned after the 2020 census, with additional listings for the next ten priorities. For the second time in a row, Minnesota was allocated the final (435th) seat. If either New York had registered 89 more residents or Minnesota had registered 26 fewer residents, New York would have been allocated the 435th seat instead.

Past apportionments

Note: The first apportionment was established by the Constitution based on population estimates made by thePhiladelphia Convention,and was not based on any census or enumeration.

Boldindicates the largest number of representatives each state has had.

Statehood order	Census	Const.	1st	2nd	3rd	4th	5th	6th	7th	8th	9th	10th	11th	12th	13th	15th	16th	17th	18th	19th	20th	21st	22nd	23rd	24th
	Year	1789	1790	1800	1810	1820	1830	1840	1850	1860	1870	1880	1890	1900	1910	1930	1940	1950	1960	1970	1980	1990	2000	2010	2020
	Effected	1789	1793	1803	1813	1823	1833	1843	1853	1863	1873	1883	1893	1903	1913	1933	1943	1953	1963	1973	1983	1993	2003	2013	2023
	Size	65	105	142	182	213	240	223	234	241	292	325	356	386	435
	State
22	AL	–	–	–	–	3	5	7	7	6	8	8	9	9	10	9	9	9	8	7	7	7	7	7	7
49	AK	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	1	1	1	1	1	1	1
48	AZ	–	–	–	–	–	–	–	–	–	–	–	–	–	1	1	2	2	3	4	5	6	8	9	9
25	AR	–	–	–	–	–	–	1	2	3	4	5	6	7	7	7	7	6	4	4	4	4	4	4	4
31	CA	–	–	–	–	–	–	–	2	3	4	6	7	8	11	20	23	30	38	43	45	52	53	53	52
38	CO	–	–	–	–	–	–	–	–	–	–	1	2	3	4	4	4	4	4	5	6	6	7	7	8
5	CT	5	7	7	7	6	6	4	4	4	4	4	4	5	5	6	6	6	6	6	6	6	5	5	5
1	DE	1	1	1	2	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
27	FL	–	–	–	–	–	–	–	1	1	2	2	2	3	4	5	6	8	12	15	19	23	25	27	28
4	GA	3	2	4	6	7	9	8	8	7	9	10	11	11	12	10	10	10	10	10	10	11	13	14	14
50	HI	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	2	2	2	2	2	2	2
43	ID	–	–	–	–	–	–	–	–	–	–	–	1	1	2	2	2	2	2	2	2	2	2	2	2
21	IL	–	–	–	–	1	3	7	9	14	19	20	22	25	27	27	26	25	24	24	22	20	19	18	17
19	IN	–	–	–	–	3	7	10	11	11	13	13	13	13	13	12	11	11	11	11	10	10	9	9	9
29	IA	–	–	–	–	–	–	–	2	6	9	11	11	11	11	9	8	8	7	6	6	5	5	4	4
34	KS	–	–	–	–	–	–	–	–	1	3	7	8	8	8	7	6	6	5	5	5	4	4	4	4
15	KY	–	2	6	10	12	13	10	10	9	10	11	11	11	11	9	9	8	7	7	7	6	6	6	6
18	LA	–	–	–	1	3	3	4	4	5	6	6	6	7	8	8	8	8	8	8	8	7	7	6	6
23	ME	–	–	–	–	7	8	7	6	5	5	4	4	4	4	3	3	3	2	2	2	2	2	2	2
7	MD	6	8	9	9	9	8	6	6	5	6	6	6	6	6	6	6	7	8	8	8	8	8	8	8
6	MA	8	14	17	20	13	12	10	11	10	11	12	13	14	16	15	14	14	12	12	11	10	10	9	9
26	MI	–	–	–	–	–	–	3	4	6	9	11	12	12	13	17	17	18	19	19	18	16	15	14	13
32	MN	–	–	–	–	–	–	–	–	2	3	5	7	9	10	9	9	9	8	8	8	8	8	8	8
20	MS	–	–	–	–	1	2	4	5	5	6	7	7	8	8	7	7	6	5	5	5	5	4	4	4
24	MO	–	–	–	–	1	2	5	7	9	13	14	15	16	16	13	13	11	10	10	9	9	9	8	8
41	MT	–	–	–	–	–	–	–	–	–	–	–	1	1	2	2	2	2	2	2	2	1	1	1	2
37	NE	–	–	–	–	–	–	–	–	–	1	3	6	6	6	5	4	4	3	3	3	3	3	3	3
36	NV	–	–	–	–	–	–	–	–	–	1	1	1	1	1	1	1	1	1	1	2	2	3	4	4
9	NH	3	4	5	6	6	5	4	3	3	3	2	2	2	2	2	2	2	2	2	2	2	2	2	2
3	NJ	4	5	6	6	6	6	5	5	5	7	7	8	10	12	14	14	14	15	15	14	13	13	12	12
47	NM	–	–	–	–	–	–	–	–	–	–	–	–	–	1	1	2	2	2	2	3	3	3	3	3
11	NY	6	10	17	27	34	40	34	33	31	33	34	34	37	43	45	45	43	41	39	34	31	29	27	26
12	NC	5	10	12	13	13	13	9	8	7	8	9	9	10	10	11	12	12	11	11	11	12	13	13	14
39	ND	–	–	–	–	–	–	–	–	–	–	–	1	2	3	2	2	2	2	1	1	1	1	1	1
17	OH	–	–	1	6	14	19	21	21	19	20	21	21	21	22	24	23	23	24	23	21	19	18	16	15
46	OK	–	–	–	–	–	–	–	–	–	–	–	–	–	8	9	8	6	6	6	6	6	5	5	5
33	OR	–	–	–	–	–	–	–	–	1	1	1	2	2	3	3	4	4	4	4	5	5	5	5	6
2	PA	8	13	18	23	26	28	24	25	24	27	28	30	32	36	34	33	30	27	25	23	21	19	18	17
13	RI	1	2	2	2	2	2	2	2	2	2	2	2	2	3	2	2	2	2	2	2	2	2	2	2
8	SC	5	6	8	9	9	9	7	6	4	5	7	7	7	7	6	6	6	6	6	6	6	6	7	7
40	SD	–	–	–	–	–	–	–	–	–	–	–	2	2	3	2	2	2	2	2	1	1	1	1	1
16	TN	–	–	3	6	9	13	11	10	8	10	10	10	10	10	9	10	9	9	8	9	9	9	9	9
28	TX	–	–	–	–	–	–	–	2	4	6	11	13	16	18	21	21	22	23	24	27	30	32	36	38
45	UT	–	–	–	–	–	–	–	–	–	–	–	–	1	2	2	2	2	2	2	3	3	3	4	4
14	VT	–	2	4	6	5	5	4	3	3	3	2	2	2	2	1	1	1	1	1	1	1	1	1	1
10	VA	10	19	22	23	22	21	15	13	11	9	10	10	10	10	9	9	10	10	10	10	11	11	11	11
42	WA	–	–	–	–	–	–	–	–	–	–	–	2	3	5	6	6	7	7	7	8	9	9	10	10
35	WV	–	–	–	–	–	–	–	–	–	3	4	4	5	6	6	6	6	5	4	4	3	3	3	2
30	WI	–	–	–	–	–	–	–	3	6	8	9	10	11	11	10	10	10	10	9	9	9	8	8	8
44	WY	–	–	–	–	–	–	–	–	–	–	–	1	1	1	1	1	1	1	1	1	1	1	1	1

Changes per census

2010

Main article:2010 United States redistricting cycle

On December 21, 2010, theU.S. Census Bureaureleased its official apportionment results for congressional representation. The changes were in effect for theU.S. elections in 2012.

Gain four	Gain two	Gain one	No change	Lose one	Lose two
1.Texas	1.Florida	1.Arizona 2.Georgia 3.Nevada 4.South Carolina 5.Utah 6.Washington	(32 states)	1.Illinois 2.Iowa 3.Louisiana 4.Massachusetts 5.Michigan 6.Missouri 7.New Jersey 8.Pennsylvania	1.New York 2.Ohio
+4	+2	+6		−8	−4
+12 seats gained total				−12 seats lost total
Allocation of congressional districts after the2010 U.S. census

2020

Main article:2020 United States redistricting cycle

Apportionment results were released on April 26, 2021:

Gain two	Gain one	No change	Lose one
1. Texas	1. Colorado 2. Florida 3. Montana 4. North Carolina 5. Oregon	(37 states)	1. California 2. Illinois 3. Michigan 4. New York 5. Ohio 6. Pennsylvania 7. West Virginia
+2	+5		−7
+7 seats gained total			−7 seats lost total
Allocation of congressional districtsin theHouse of Representativesafter the2020 U.S. census

List of apportionments

The size of theU.S. House of Representativeshas increased and decreased as follows:

Effective date	Size	Change	Legal provision	Reason and/or comments
March 4, 1789	59	n/a	Const. Art. I, § 2, cl. 3	Seats apportioned by the Constitution based on population estimates made by thePhiladelphia Convention.Only 11 of the original 13 states had ratified the Constitution by this time.
November 21, 1789	64	5		North Carolinaratified the Constitution with the seats apportioned by the Constitution.
May 29, 1790	65	1		Rhode Islandratified the Constitution with the seat apportioned by the Constitution.
March 4, 1791	67	2	1Stat.191	Vermontadmitted.
June 1, 1792	69	2		Kentuckyadmitted.
March 4, 1793	105	36	1Stat.253(Apportionment Act of 1792)	Apportionment following thefirst census (1790).First to use theJefferson method.
June 1, 1796	106	1	1Stat.491	Tennesseeadmitted.
March 1, 1803	107	1	2Stat.175	Ohioadmitted.
March 4, 1803	142	35	2Stat.128	Apportionment following thesecond census (1800).
April 30, 1812	143	1	2Stat.703	Louisianaadmitted.
March 4, 1813	182	39	2Stat.669	Apportionment following thethird census (1810).
December 11, 1816	183	1	3Stat.290	Indianaadmitted.
December 10, 1817	184	1	3Stat.349	Mississippiadmitted.
December 3, 1818	185	1	3Stat.430	Illinoisadmitted.
December 14, 1819	186	1	3Stat.492	Alabamaadmitted.
March 15, 1820			3Stat.555	Maineadmitted, 7 seats transferred fromMassachusetts.
August 10, 1821	187	1	3Stat.547	Missouriadmitted.
March 4, 1823	213	26	3Stat.651	Apportionment following thefourth census (1820).
March 4, 1833	240	27	4Stat.516	Apportionment following thefifth census (1830).
June 15, 1836	241	1	5Stat.51	Arkansasadmitted.
January 26, 1837	242	1	5Stat.50	Michiganadmitted.
March 4, 1843	223	19	5Stat.491	Apportionment following thesixth census (1840).First to use theWebster method.Became theonly time the size of the House was reduced,except for the minor readjustments in 1863 and 1963.
March 3, 1845	224	1	5Stat.743	Floridaadmitted.
December 29, 1845	226	2	5Stat.798	Texas annexedand admitted.
December 28, 1846	228	2	5Stat.743 9Stat.52	Iowaadmitted.
May 29, 1848	230	2	9Stat.58 9Stat.235	Wisconsinadmitted.
March 4, 1849	231	1	9Stat.235	Additional seat apportioned to Wisconsin.
September 9, 1850	233	2	9Stat.452	Californiaadmitted.
March 4, 1853			9Stat.432	Apportionment following theseventh census (1850).First to use theHamilton/Vinton(largest remainder) method.
	234	1	10Stat.25	Additional seat apportioned to California
May 11, 1858	236	2	11Stat.166	Minnesotaadmitted.
February 14, 1859	237	1	11Stat.383	Oregonadmitted.
January 29, 1861	238	1	12Stat.126	Kansasadmitted
June 2, 1862	239	1	12Stat.411	California apportioned an extra seat.
March 4, 1863	233	6	9Stat.432	Apportionment following theeighth census (1860),in accordance with the 1850 act, which provided for an apportionment of 233 seats.
	241	8	12Stat.353	Supplemental apportionment of 8 seats (1 each for Pennsylvania, Ohio, Kentucky, Illinois, Iowa, Minnesota, Vermont, and Rhode Island), for an overall increase of 2 seats in the 38th Congress.
June 20, 1863			12Stat.633	West Virginiaadmitted,three seats transferred fromVirginia.
October 31, 1864	242	1	13Stat.32	Nevadaadmitted
March 1, 1867	243	1	14Stat.391	Nebraskaadmitted
March 4, 1873	283	40	17Stat.28	Apportionment following theninth census (1870),replacing the 1850 act
	292	9	17Stat.192	Supplemental apportionment added one seat each for nine states
August 1, 1876	293	1	13Stat.34	Coloradoadmitted
March 4, 1883	325	32	22Stat.5	Apportionment following thetenth census (1880).
November 2, 1889	328	3	25Stat.679	NorthandSouthDakota admitted, with one and two seats respectively.
November 8, 1889	329	1	25Stat.679	Montanaadmitted.
November 11, 1889	330	1	25Stat.679	Washingtonadmitted.
July 3, 1890	331	1	26Stat.215	Idahoadmitted.
July 10, 1890	332	1	26Stat.222	Wyomingadmitted.
March 4, 1893	356	24	26Stat.735	Apportionment following theeleventh census (1890).
January 4, 1896	357	1	28Stat.109	Utahadmitted.
March 4, 1903	386	29	31Stat.733	Apportionment following thetwelfth census (1900)
November 16, 1907	391	5	34Stat.271	Oklahomaadmitted
January 6, 1912	393	2	37Stat.39,incorporating 36Stat.557	New Mexicoadmitted
February 14, 1912	394	1		Arizonaadmitted
March 4, 1913	435	41	37Stat.13(Apportionment Act of 1911,§§1–2)	Apportionment following thethirteenth census (1910).Process returned to the Webster method.
March 4, 1933			46Stat.26(Reapportionment Act of 1929)	Apportionment following thefifteenth census (1930).The size of the House became permanently capped at 435 seats under the Reapportionment Act of 1929.
January 3, 1943			46Stat.26(Reapportionment Act of 1929) 54Stat.162	Apportionment following thesixteenth census (1940).First to use theHuntington–Hill method.
January 3, 1953			55Stat.761	Apportionment following theseventeenth census (1950)
January 3, 1959	436	1	72Stat.345	Alaskaadmitted.
August 21, 1959	437	1	73Stat.8,§8	Hawaiiadmitted.
January 3, 1963	435	2	72Stat.345 73Stat.8 2 U.S.C.§ 2a	Apportionment following theeighteenth census (1960)
January 3, 1973			2 U.S.C.§ 2a	Apportionment following thenineteenth census (1970).
January 3, 1983				Apportionment following thetwentieth census (1980).
January 3, 1993				Apportionment following thetwenty-first census (1990).
January 3, 2003				Apportionment following thetwenty-second census (2000).
January 3, 2013				Apportionment following thetwenty-third census (2010).
January 3, 2023				Apportionment following thetwenty-fourth census (2020).

See also

• List of U.S. states by population
• List of U.S. states by historical population(tables of state populations since 1790)
• Electoral vote changes between United States presidential elections

Notes

• Delegate counts initalicsrepresent temporary counts assigned by Congress until the next decennial census or by the U.S. Constitution in 1789 until the first U.S. census.
• Elections held in the year of a census use the apportionment determined by the previous census.

Citations

References

• Balinski, Michael L.; Young, H. Peyton (1982).Fair Representation: Meeting the Ideal of One Man, One Vote.New Haven, CT: Yale University Press.ISBN0-8157-0090-3.
• Foster, Robert (1895).Commentaries on the Constitution of the United States: Historical and Judicial.Vol. 1. Boston: The Boston Book Co. pp. 329–446.
• Hamilton, Alexander;Madison, James;Jay, John(1831).The Federalist.Hallowell: Glazier, Masters & Co.ISBN0-8239-5735-7.
• Edelman, Paul H. (2006). "Getting the Math Right: Why California Has Too Many Seats in the House of Representatives".Vanderbilt Law Review.102(March). Nashville: Vanderbilt University: 297.
• Kromkowski, Charles A.; Kromkowski, John A. (1991)."Why 435? A Question of Political Arithmetic"(PDF).Polity.24(Fall 1991): 129–145.doi:10.2307/3234988.JSTOR3234988.S2CID155209561.RetrievedOctober 17,2013.
• Agnew, Robert A. (2008)."Optimal Congressional Apportionment"(PDF).American Mathematical Monthly.115(April). Mathematical Association of America: 297–303.doi:10.1080/00029890.2008.11920530.JSTOR27642473.S2CID14596741.

Further reading

• Stinebrickner-Kauffman, Taren (2004). "Counting Matters: Prison Inmates, Population Bases, and" One Person, One Vote "".Virginia Journal of Social Policy & the Law.11(Winter). Chicago: 229.

External links

• Congressional Apportionment by the U.S. Census Bureau