# United States congressional apportionment

United States congressional apportionment is the process[1] by which seats in the United States House of Representatives are distributed among the 50 states according to the most recent decennial census mandated by the United States Constitution. Each state is apportioned a number of seats which approximately corresponds to its share of the aggregate population of the 50 states.[2] Every state is constitutionally guaranteed at least one seat.

Allocation of congressional districts after the 2010 U.S. Census
Allocation of congressional districts after the 2000 U.S. Census
The 435 seats of the House grouped by state (post-2010 Census reapportionment)
Allocation of seats by state, as percentage of overall number of representatives in the House, 1789-2020 Census

The number of voting seats in the House of Representatives has been 435 since 1913, capped at that number by the Reapportionment Act of 1929—except for a temporary (1959–1962) increase to 437 when Alaska and Hawaii were admitted into the Union.[3] The Huntington–Hill method of equal proportions has been used to distribute the seats among the states since the 1940 census reapportionment.[1][4] Federal law requires the Clerk of the United States House of Representatives to notify each state government of the number of seats apportioned to the state no later than January 25 of the year immediately following each decennial census.

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

## Constitutional context

Article One, Section 2, Clause 3 of the United States Constitution initially 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;…

"Three-fifths of all other persons" refers to the inclusion of 35 of the slaves in the population base.

Following the end of the Civil War, the first of those provisions was superseded by Section 2 of the Fourteenth Amendment: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.[5] 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.

## 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 the U.S. Electoral College. Under Article II, Section 1, Clause 2 of 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 the Clerk of the House of Representatives to 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 of congressional districts—geographical areas within the state of approximately equal population—in a process called redistricting.[6]

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 during the 2020 presidential election was still based on the 2010 census results.

## 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 currently set at 435. There are an additional five delegates to the House of Representatives. They represent the District of Columbia and the territories of American Samoa, Guam, the Northern Mariana Islands, which first elected a representative in 2008,[7] and the U.S. Virgin Islands. Puerto Rico also elects a resident commissioner every four years.

### Controversy and history

Since 1789, when the federal government began operating 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 Washington agreed that the original representation proposed during the Constitutional Convention (one representative for every 40,000) was inadequate and supported an alteration to reduce that number to 30,000.[8] This was the only time that Washington pronounced an opinion on any of the actual issues debated during the entire convention.[9]

In Federalist No. 55, James Madison argued 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; ...[10]

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.[10]

#### Global comparison and disparities

When talking about the populations within California's reapportioned House districts in 1951, a report from Duke University found that "[there] is not an excessive disparity in district populations, but [the populations and disparities are] perhaps larger than necessary."[11] If the House continued to expand as it did prior to the Reapportionment Act of 1929, it would currently have 1,156 members (still just the second largest lower house, after China).[12] This would give the representatives, on average, about 287 thousand constituents, on par with Japan's National Diet.

The United States also has comparatively massive constituencies for OECD members, with almost three times more constituents per legislator on average than Japan and Mexico.[12] The U.S. has the third most populous average legislative districts in the world (second if the EU's European Parliament is not included).

### Membership cap

The Apportionment 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 of Arizona and New Mexico as 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 the newly elected Republican majority may have feared the effect such a reapportionment would have on their future electoral prospects.[13][14] A reapportionment in 1921 in the traditional fashion would have increased the size of the House to 483 seats[citation needed], 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.[15]

In 1929 Congress (with Republican control of both houses of Congress and the presidency) passed the Reapportionment Act of 1929 which capped the size of the House at 435 (the then current number) 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 of Alaska and Hawaii into the Union.[16]

Two states – Wyoming and Vermont, – have populations smaller than the average for a single district, although none of those states have fewer people than the least populous congressional districts (as of the 2020 census, Montana's two districts). As of May 2016, there is approximately one representative for every 720,000 people in the country.

### Proposed expansion

The first proposed amendment to the Constitution within the Bill of Rights attempted to set a pattern for growth of the House along with the population, but has not been ratified.

Article the first ... After the first enumeration required 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.[17]

With the nation's population reaching approximately 308.7 million according to the 2010 census, the proposed amendment would have called for an up-to 6,000-member House.[18][19][20]

One proposal to fix 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's method of allocation for proportional representation, it would give the least populous state (which has been Wyoming since 1990) one representative and then create districts in other states with the same population.[21]

Another proposed expansion rule, the cube root rule,[22] calls for the membership of the legislature to be based on the cube 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 the national population exceeds the 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).[23]

On May 21, 2001, Rep. Alcee Hastings sent a dear colleague letter pointing out that U.S. expansion of its legislature had not kept pace with other countries.[24]

In 2007, during the 110th Congress, Representative Tom Davis introduced a bill in the House of Representatives that would add two seats to the House, one for Utah and one for the District 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 the 111th Congress. In February 2009 the Senate adopted the measure 61–37. In April 2010, however, House leaders decided to shelve the proposal.[25]

## Apportionment methods

Apportionment in the House of the US population, 2010-2019
State Population Percent House Percent
2019 2010 2019[note 1] 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%
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%
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%
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%
Vermont 0.19% 0.20% 0.23% 0.23%
Wyoming 0.18% 0.18% 0.23% 0.23%
1. ^ 2019 numbers are calculations from estimated population data

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 the Constitution, five distinct apportionment methods have been used.

The first apportionment was contained in Art. I, § 2, cl. 3 of the Constitution. After the first Census in 1790, Congress passed the Apportionment Act of 1792 and adopted the Jefferson method to apportion U.S. Representatives to the states based on population.[26] The Jefferson method required fractional remainders to be discarded when calculating each state's total number of U.S. Representatives and was used until the 1830 census.[27][28][29][30] The Webster method, proposed in 1832 by Daniel Webster and adopted for the 1840 Census, allocated an additional Representative to states with a fractional remainder greater than 0.5.[31] The Hamilton/Vinton (largest remainder) method was used from 1850[32][33][34][35][36][37] until 1900. The Vinton or Hamilton method was shown to be susceptible to an apportionment paradox.[38] The Apportionment 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 the Huntington–Hill method or method of equal proportions, was adopted in 1941 for reapportionment based on the 1940 census and beyond.[1][4][39][40] The revised method was necessary in the context of the cap on the number of Representatives set in the Reapportionment Act of 1929.

### The method of equal proportions

The apportionment method currently used is the method of equal proportions, which minimizes the percentage differences in the number of people per representative among the different states.[41] 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.[42]

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 the geometric mean of the number of seats it currently holds in the assignment process, n (initially 1), and the number of seats it would hold if the seat were assigned to it, n+1. Symbolically, the priority number An is

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

where P is the population of the state, and n is the number of seats it currently holds before the possible allocation of the next seat. An equivalent, recursive definition is

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

where n is still the number of seats the state has before allocation of the next (in other words, for the mth allocation, n = m-1, where m > 1), and for n = 1, the initial A1 is explicitly defined by the non-recursive formula as

${\displaystyle A_{1}={\frac {P}{\sqrt {2}}}}$

Consider the reapportionment following the 2010 U.S. Census: beginning with all states initially being allocated one seat, the largest value of A1 corresponds to the largest state, California, which is allocated seat 51. After being allocated its 2nd seat, its priority value decreases to its A2 value, which is reordered to a position back in line. The 52nd seat goes to Texas, the 2nd largest state, because its A1 priority value is larger than the An of any other state. However, the 53rd seat goes back to California because its A2 priority value is larger than the An of any other state. The 54th seat goes to New York because its A1 priority value is larger than the An of any other state at this point. This process continues until all remaining seats are assigned. Each time a state is assigned a seat, n is 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 Census 2010 Ranking of Priority Values[43] shows the order in which seats 51–435 were apportioned after the 2010 Census, with additional listings for the next five priorities. Minnesota was allocated the final (435th) seat. North Carolina missed 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.[44]

The Census 2020 Ranking of Priority Values[45] shows 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.[46][47]

## Past apportionments

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

Bold indicates the largest number of representatives each state has had.

## Changes following the 2010 censuses

On December 21, 2010, the U.S. Census Bureau released its official apportionment results for congressional representation. The changes were in effect for the U.S. elections in 2012.[48]

Gain four Gain two Gain one No change Lose one Lose two
1. Texas 1. Florida 1. Arizona
2. Georgia
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

## Changes following the 2020 censuses

Apportionment results were released on April 26, 2021:

Gain two Gain one No change Lose one
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

## List of apportionments

The size of the U.S. House of Representatives has increased and decreased as follows[49]

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
November 21, 1789 64   5 North Carolina ratified the Constitution with the seats apportioned by the Constitution
May 29, 1790 65   1 Rhode Island ratified the Constitution with the seat apportioned by the Constitution
March 4, 1791 67   2 Stat. 191 Vermont admitted
June 1, 1792 69   2 Kentucky admitted
March 4, 1793 105   36 Stat. 253 (Apportionment Act of 1792) Apportionment following the First Census
June 1, 1796 106   1 Stat. 491 Tennessee admitted
March 1, 1803 107   1 Stat. 175 Ohio admitted.
March 4, 1803 142   35 Stat. 128 Apportionment following the Second Census.
April 30, 1812 143   1 Stat. 703 Louisiana admitted.
March 4, 1813 182   39 Stat. 669 Apportionment following the Third Census.
December 11, 1816 183   1 Stat. 290 Indiana admitted.
December 10, 1817 184   1 Stat. 349 Mississippi admitted.
December 3, 1818 185   1 Stat. 430 Illinois admitted.
December 14, 1819 186   1 Stat. 492 Alabama admitted.
March 15, 1820   Stat. 555 Maine admitted, 7 seats transferred from Massachusetts
August 10, 1821 187   1 Stat. 547 Missouri admitted
March 4, 1823 213   26 Stat. 651 Apportionment following the Fourth Census
March 4, 1833 240   27 Stat. 516 Apportionment following the Fifth Census
June 15, 1836 241   1 Stat. 51 Arkansas admitted
January 26, 1837 242   1 Stat. 50 Michigan admitted
March 4, 1843 223   19 Stat. 491 Apportionment following the Sixth Census, the only time the size of the House was reduced, except for the minor readjustments in 1863 and 1963.
March 3, 1845 224   1 Stat. 743 Florida admitted.
December 29, 1845 226   2 Stat. 798 Texas annexed and admitted.
December 28, 1846 228   2 Stat. 743
Stat. 52
May 29, 1848 230   2 Stat. 58
Stat. 235
March 4, 1849 231   1 Stat. 235 Additional seat apportioned to Wisconsin.
September 9, 1850 233   2 Stat. 452 California admitted.
March 4, 1853   Stat. 432 Apportionment following the Seventh Census.
234   1 10 Stat. 25 Additional seat apportioned to California[b]
May 11, 1858 236   2 11 Stat. 166 Minnesota admitted.
February 14, 1859 237   1 11 Stat. 383 Oregon admitted.
January 29, 1861 238   1 12 Stat. 126 Kansas admitted
June 2, 1862 239   1 12 Stat. 411 California apportioned an extra seat
March 4, 1863 233   6 Stat. 432 Apportionment following the Eighth Census, in accordance with the 1850 act, which provided for an apportionment of 233 seats
241   8 12 Stat. 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   12 Stat. 633 West Virginia admitted, three seats transferred from Virginia
March 4, 1873 283   40 17 Stat. 28 Apportionment following the Ninth Census, replacing the 1850 act
292   9 17 Stat. 192 Supplemental apportionment added one seat each for nine states
March 4, 1883 325   32 22 Stat. 5 Apportionment following the Tenth Census.
November 2, 1889 328   3 25 Stat. 679 North and South Dakota admitted, with one and two seats respectively.
November 8, 1889 329   1 25 Stat. 679 Montana admitted.
November 11, 1889 330   1 25 Stat. 679 Washington admitted.
July 3, 1890 331   1 26 Stat. 215 Idaho admitted.
July 10, 1890 332   1 26 Stat. 222 Wyoming admitted.
March 4, 1893 356   24 26 Stat. 735 Apportionment following the Eleventh Census.
January 4, 1896 357   1 28 Stat. 109 Utah admitted.
March 4, 1903 386   29 31 Stat. 733 Apportionment following the Twelfth Census (1900)
November 16, 1907 391   5 34 Stat. 271 Oklahoma admitted
January 6, 1912 393   2 37 Stat. 39, incorporating 36 Stat. 557 New Mexico admitted
February 14, 1912 394   1 37 Stat. 39, incorporating 36 Stat. 557 Arizona admitted
March 4, 1913 435   41 37 Stat. 13 (Apportionment Act of 1911, §§1–2) Apportionment following the Thirteenth Census (1910)
March 4, 1933   46 Stat. 26 (Reapportionment Act of 1929) Apportionment following the Fifteenth Census (1930)[c]
January 3, 1943   46 Stat. 26 (Reapportionment Act of 1929)
54 Stat. 162
Apportionment following the Sixteenth Census (1940)
January 3, 1953   55 Stat. 761 Apportionment following the Seventeenth Census[d]
August 21, 1959 437   1 73 Stat. 8, §8 Hawaii admitted
January 3, 1963 435   2 72 Stat. 345
73 Stat. 8
2 U.S.C. § 2a
Apportionment following the Eighteenth Census[e]
January 3, 1973   2 U.S.C. § 2a Apportionment following the Nineteenth Census
January 3, 1983   2 U.S.C. § 2a Apportionment following the Twentieth Census
January 3, 1993   2 U.S.C. § 2a Apportionment following the Twenty-First Census
January 3, 2003   2 U.S.C. § 2a Apportionment following the Twenty-Second Census
January 3, 2013   2 U.S.C. § 2a Apportionment following the Twenty-Third Census
January 3, 2023   2 U.S.C. § 2a Apportionment following the Twenty-Fourth Census

## Notes

• Delegate counts in italics represent 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.
1. ^ Congress failed to pass any reapportionment to implement the 1920 United States Census so despite population shift, distribution of seats from 1913 remained in effect until 1933.
2. ^ The 1850 Apportionment bill provided a method to be used in future reapportionments, as well as establishing the then-current 233 as the number of seats to be apportioned after future censuses. Due to census returns being incomplete in California, an additional act provided that California retain the same representation it had when admitted, until a new census could be taken. California would otherwise have lost one seat, and so the total number of seats was increased by one to 234.
3. ^ Congress failed to reapportion in 1923, following the Fourteenth Census (1920).
4. ^ Pub.L. 77–291 amended section 22 of the Reapportionment Act of 1929 by wholly replacing its text.
5. ^ The Reapportionment Act of 1929 stated that the "then existing number of Representatives" would be apportioned after each census, which would have dictated an apportionment of 437 seats, but the Alaska Statehood Act and Hawaii Admission Act explicitly stated that the new seats were temporary increases. Both acts included the phrasing "That such temporary increase in the membership shall not operate to either increase or decrease the permanent membership of the House of Representatives as prescribed in the Act of August 8, 1911 (37 Stat. 13) nor shall such temporary increase affect the basis of apportionment established by the Act of November 15, 1941 (55 Stat. 761; 2 U.S.C. § 2a), for the Eighty-third Congress and each Congress thereafter."[50]
1. ^ a b c Kristin D. Burnett (November 1, 2011). "Congressional Apportionment (2010 Census Briefs C2010BR-08)" (PDF). U.S. Department of Commerce, Economics and Statistics Administration. Retrieved February 25, 2015.
2. ^ The populations of Washington, D.C. and federal territories are not included in this figure.
3. ^ Public Law 62-5 of 1911.
4. ^ a b "The History of Apportionment in America". American Mathematical Society. Retrieved February 15, 2009.
5. ^ Rendered moot by the Revenue Act of 1924 and Indian Citizenship Act of 1924.
6. ^
7. ^ Bush signs federalization bill Archived February 13, 2009, at the Wayback Machine, Agnes E. Donato, Saipan Tribune, May 10, 2008.
8. ^ Goldberg, Jonah (January 15, 2001). "George Will Called Me An Idiot". National Review. Archived from the original on February 13, 2009. Retrieved April 11, 2018.
9. ^ Madison's notes on the Constitutional Convention - Tuesday September 17, 1787
10. ^ a b "The Federalist #55". constitution.org. Retrieved June 23, 2020.
11. ^ Todd, James (1952). "Law and Contemporary Problems: Legislative Apportionment (Chapter Title: The Apportionment Problem Faced by the States)". Law and Contemporary Problems. Durham, North Carolina: Duke University. 17 (2): 314–337. eISSN 1945-2322. ISSN 1945-2322.
12. ^ a b DeSilver, Drew (May 31, 2018). "U.S. population keeps growing, but House of Representatives is same size as in Taft era". Pew Research Center.
13. ^ Balinski, Michel; Young, H. Peyton. Fair Representation, Meeting The Ideal of One Man One vote". p. 51.
14. ^ "Congressional Apportionment". NationalAtlas.gov. Archived from the original on February 28, 2009. Retrieved February 15, 2009.
15. ^ "Apportionment of Representatives in Congress". CQ Researcher by CQ Press. ISSN 1942-5635.
16. ^ "Proportional Representation". Washington, D.C.: Office of the Historian, United States House of Representatives. Retrieved September 21, 2018.
17. ^ "Constitutional Amendments Not Ratified". United States House of Representatives. Archived from the original on September 27, 2007. Retrieved September 30, 2007.
18. ^ Stone, Lyman (October 17, 2018). "Pack the House: How to Fix the Legislative Branch". Mere Orthodoxy. Retrieved September 17, 2019.
19. ^ Matthews, Dylan (June 4, 2018). "The case for massively expanding the US House of Representatives, in one chart". Vox. Retrieved September 17, 2019.
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26. ^ 3 Annals of Cong. 539 (1792)
27. ^ Act of Jan. 14, 1802, 2 Stat. 128
28. ^ Act of Dec. 21, 1811, 2 Stat. 669
29. ^ Act of Mar. 7, 1822, 3 Stat. 651
30. ^ Act of May 22, 1832, 4 Stat. 516
31. ^ Act of 25 June 1842, ch 46, 5 Stat. 491
32. ^ Act of May 23, 1850, 9 Stat. 432-433
33. ^ Act of 1862, 12 Stat. 572
34. ^ Act of 1872, 17 Stat. 28
35. ^ Act of 1882, 22 Stat. 5
36. ^ Act of 1891
37. ^ Act of 1901, 31 Stat. 733
38. ^ "Congressional Apportionment-Historical Perspective". U.S. Census Bureau. Retrieved October 27, 2013..
39. ^ "2 USC §2a". Cornell University Law School, Legal Information Institute. Retrieved May 13, 2008.
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50. ^ See, e.g., section 8 of the Hawaii Admission Act, 73 Stat. 8.