Office of the Clerk

Congressional Apportionment

1st to 22nd Census (1790-2000)
The founders designed the House of Representatives to represent the people rather than the states, which each send two Members to the U.S. Senate. Article I, Section II of the Constitution provides each state at least one U.S. Representative, while the size of a state’s delegation to the House depends on its total population. Based on the 1787 national population, each House Member in the First Federal Congress (1789–1791) represented 30,000 citizens. As U.S. territory expanded and the population grew, the Membership of House of Representatives increased and individual Members’ constituencies were enlarged.

Floor of the House of Representatives of the United States 29th Congress, 1845
Print, 12.5 x 19 inches
Collection of U.S. House of Representatives

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How is apportionment determined?

The Constitution assigned the original apportionment of the Representatives between the different states based on population in 1787. These numbers remained in effect for the 1st and 2nd Congresses (1789–1793). Using five different methods over time, all with the aim of dividing representation among the states proportionately, Congress based subsequent apportionments on changes in state population as recorded in each decennial census since 1790.² Up to and including the 13th Census in 1910, Congress enacted a law designating the specific changes in the actual number of Representatives as well as the increase in the representation ratio. In 1941, Congress permanently adopted the “Method of Equal Proportion” to determine apportionment. The U.S. Census Bureau provides more information on this method of computing apportionment.

How many Members currently serve in the House of Representatives?

The total membership of the House of Representatives is 440 Members. There are 435 Representatives from the 50 states. In addition, four, non-voting Delegates represent the District of Columbia and the U.S. territories of Guam, the U.S. Virgin Islands, and American Samoa. A non-voting Resident Commissioner, serving a four-year term, represents the Commonwealth of Puerto Rico.

Why are there 435 voting Members of the House of Representatives?

In order to keep the House at a manageable number, Congress twice set the size of the House at 435 voting Members—the then-existing number of Representatives. In 1911, Congress designated the number of Representatives to be 433, with provisions made for two additional Members when Arizona and New Mexico were admitted to the Union (see Act of August 8, 1911, ch. 5, 37 Stat 13). The 63rd Congress (1913–1915) was the first to have 435 Members. The Permanent Apportionment Act of 1929 capped the Membership at that level, creating a procedure for reapportioning state delegations in the House under “the then existing number of Representatives” (see Act of June 18, 1929, ch. 28, 46 Stat 21).

What happens when new, voting Members are added to the House of Representatives?

The admission of Alaska and Hawaii into the Union as states in 1959 serves as the last example of the addition of new voting Members to the U.S. House of Representatives. Congress temporarily added one new Representative for each state in the 86th and 87th Congresses (1959–1963), bringing the total number of Representatives in the House to 437. In 1963, when the apportionment mandated by the 18th Census (1960) took effect, the total number of Representatives in the House returned to 435 for the 88th Congress (1963–1965).

What is the process for the reapportionment of seats in the House of Representatives?

Presently the U.S. Census Bureau must deliver the results of a decennial census to the President of the United States within nine months of the census date. Within a week of the opening of the next Congress, the President is required by law to report the census results to the Clerk of the House. Within 15 days, the Clerk must then disclose to the governor of each state how many seats his or her state is entitled. The state legislatures are charged with redrawing a state’s congressional districts. Apportionments take affect two Congresses (three years) after the last census. The last (22nd) Census was conducted on April 1, 2000 and apportionment took effect for the 108th Congress (2003-2005). For more information, see the United States Census Bureau website.

Representatives Apportioned to Each State 1st to 22nd Census (1790-2000)


AL	..	..	..	..	3	5	7	7	6	8	8	9	9	10	9	9	9	8	7	7	7	7
AK	..	..	..	..	..	..	..	..	..	..	..	..	..	..	..	..	..	1	1	1	1	1
AZ⁴	..	..	..	..	..	..	..	..	..	..	..	..	..	1	1	2	2	3	4	5	6	8
AR	..	..	..	..	..	..	1	2	3	4	5	6	7	7	7	7	6	4	4	4	4	4
CA^4,5	..	..	..	..	..	..	..	2	3	4	6	7	8	11	20	23	30	38	43	45	52	53
CO	..	..	..	..	..	..	..	..	..	..	1	2	3	4	4	4	4	4	5	6	6	7
CT	5	7	7	7	6	6	4	4	4	4	4	4	5	5	6	6	6	6	6	6	6	5
DE	1	1	1	2	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
FL	..	..	..	..	..	..	..	1	1	2	2	2	3	4	5	6	8	12	15	19	23	25
GA	3	2	4	6	7	9	8	8	7	9	10	11	11	12	10	10	10	10	10	10	11	13
HI	..	..	..	..	..	..	..	..	..	..	..	..	..	..	..	..	..	2	2	2	2	2
ID	..	..	..	..	..	..	..	..	..	..	..	1	1	2	2	2	2	2	2	2	2	2
IL	..	..	..	..	1	3	7	9	14	19	20	22	25	27	27	26	25	24	24	22	20	19
IN	..	..	..	..	3	7	10	11	11	13	13	13	13	13	12	11	11	11	11	10	10	9
IA	..	..	..	..	..	..	..	2	6	9	11	11	11	11	9	8	8	7	6	6	5	5
KS⁴	..	..	..	..	..	..	..	..	1	3	7	8	8	8	7	6	6	5	5	5	4	4
KY⁴	..	2	6	10	12	13	10	10	9	10	11	11	11	11	9	9	8	7	7	7	6	6
LA	..	..	..	..	3	3	4	4	5	6	6	6	7	8	8	8	8	8	8	8	7	7
ME⁶	..	..	..	..	7	8	7	6	5	5	4	4	4	4	3	3	3	2	2	2	2	2
MD	6	8	9	9	9	8	6	6	5	6	6	6	6	6	6	6	7	8	8	8	8	8
MA⁶	8	14	17	20	13	12	10	11	10	11	12	13	14	16	15	14	14	12	12	11	10	10
MI	..	..	..	..	..	..	3	4	6	9	11	12	12	13	17	17	18	19	19	18	16	15
MN	..	..	..	..	..	..	..	..	2	3	5	7	9	10	9	9	9	8	8	8	8	8
MS	..	..	..	..	1	2	4	5	5	6	7	7	8	8	7	7	6	5	5	5	5	4
MO⁴	..	..	..	..	1	2	5	7	9	13	14	15	16	16	13	13	11	10	10	9	9	9
MT	..	..	..	..	..	..	..	..	..	..	..	1	1	2	2	2	2	2	2	2	1	1
NE	..	..	..	..	..	..	..	..	..	1	3	6	6	6	5	4	4	3	3	3	3	3
NV	..	..	..	..	..	..	..	..	..	1	1	1	1	1	1	1	1	1	1	2	2	3
NH	3	4	5	6	6	5	4	3	3	3	2	2	2	2	2	2	2	2	2	2	2	2
NJ	4	5	6	6	6	6	5	5	5	7	7	8	10	12	14	14	14	15	15	14	13	13
NM⁴	..	..	..	..	..	..	..	..	..	..	..	..	..	1	1	2	2	2	2	3	3	3
NY	6	10	17	27	34	40	34	33	31	33	34	34	37	43	45	45	43	41	39	34	31	29
NC	5	10	12	13	13	13	9	8	7	8	9	9	10	10	11	12	12	11	11	11	12	13
ND	..	..	..	..	..	..	..	..	..	..	..	1	2	3	2	2	2	2	1	1	1	1
OH	..	..	..	6	14	19	21	21	19	20	21	21	21	22	24	23	23	24	23	21	19	18
OK	..	..	..	..	..	..	..	..	..	..	..	..	..	8	9	8	6	6	6	6	6	5
OR	..	..	..	..	..	..	..	..	1	1	1	2	2	3	3	4	4	4	4	5	5	5
PA	8	13	18	23	26	28	24	25	24	27	28	30	32	36	34	33	30	27	25	23	21	19
RI	1	2	2	2	2	2	2	2	2	2	2	2	2	3	2	2	2	2	2	2	2	2
SC	5	6	8	9	9	9	7	6	4	5	7	7	7	7