Equal Representation

1. The map

Click a state to see its seat count, population per seat, and its district map. Colors show the number of seats: lighter for fewer, darker for more. Grey states are not finished yet.

2. The original wording

The Constitution's first Article sets up the House of Representatives. The provisions that govern how seats are divided among the states, as they were written in 1787, read:

Article I, Section 2, Clause 3 (apportionment)

"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 actual Enumeration shall be made within three Years after the first Meeting of the Congress of the United States, and within every subsequent Term of ten Years, in such Manner as they shall by Law direct. The Number of Representatives shall not exceed one for every thirty Thousand, but each State shall have at least one Representative; and until such enumeration shall be made, the State of New Hampshire shall be entitled to chuse three, Massachusetts eight, Rhode-Island and Providence Plantations one, Connecticut five, New-York six, New Jersey four, Pennsylvania eight, Delaware one, Maryland six, Virginia ten, North Carolina five, South Carolina five, and Georgia three."

Article I, Section 2, Clause 1 (who votes)

"The House of Representatives shall be composed of Members chosen every second Year by the People of the several States, and the Electors in each State shall have the Qualifications requisite for Electors of the most numerous Branch of the State Legislature."

Article I, Section 4 (how elections are run)

"The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Places of chusing Senators."

Two later changes that matter here

The "three fifths" rule in Article I was replaced by Section 2 of the Fourteenth Amendment (1868), which counts "the whole number of persons in each State, excluding Indians not taxed." The House size was fixed at 435 by Congress in 1911 (with 1929 and later statutes setting the apportionment method), so the one-per-30,000 limit in the original text no longer caps the number of seats.

3. The philosophy

Two ideas run through the text.

• Representation follows people. Seats are assigned to states according to their population, and each state must have at least one. The House was meant to represent the people directly, rather than states as equal units (that was the Senate's job).
• Each district should hold about the same number of people. The Constitution does not say this in so many words. The Supreme Court read it into "chosen by the People of the several States" in Wesberry v. Sanders (1964): "as nearly as is practicable one man's vote in a congressional election is to be worth as much as another's." Under that reading, a district with twice as many people gives its voters half the influence of voters elsewhere.

These two ideas together produce a simple target: each state gets a number of seats proportional to its population, and each seat covers roughly the same number of people. With the 2020 census, that is about 761,000 people per seat nationally (331.1 million ÷ 435). The districts on this site aim for that target inside each state.

Our districts test the principle, not a final plan. They balance population to within about 0.1% of each state's target, but they do not yet check contiguity or respect county or city lines. A real redistricting would have to follow those rules, and reasonable people draw different maps that meet the same population target.

4. How the districts were drawn

1. Seats per state. The 435 seats were divided using the Method of Equal Proportions (2 U.S.C. §2a), applied to the 2020 Census apportionment population. Each state starts with one seat, then seats go to the state with the highest priority value until 435 are assigned. Our check reproduces the official 2020 result exactly.
2. Block populations. The Census Bureau's 2020 P.L. 94-171 redistricting file gives the population of every census block (about 8 million nationwide). Each block's population is attached to its geographic center.
3. Splitting. Each state is split recursively. A region with n seats is divided at the point that gives half its population to ⌊n/2⌋ seats and half to ⌈n/2⌉ seats, cutting along its longer side. This is repeated until each region is one district.
4. Result. Every block belongs to exactly one district. District populations land within about 0.1% of the state target.

Limits. Straight cuts do not check contiguity, follow county or city lines, or account for communities of interest, all of which real plans must consider. Dense corridors produce narrow districts. In Colorado, most residents live along the Front Range, so equal-population cuts there yield long, thin districts (the red strip on Colorado's map is one of them). Real plans would reshape such districts to be more compact. The method uses resident population (the block data), while the official apportionment figures also add overseas military and federal employees, which is why the target differs very slightly from the official ideal.

5. Sources

• U.S. Constitution, Article I, §§ 2 and 4; Amendment XIV, § 2.
• 2 U.S.C. §§ 2a–2b (apportionment method).
• Wesberry v. Sanders, 376 U.S. 1 (1964); Karcher v. Daggett, 462 U.S. 725 (1983); Evenwel v. Abbott, 578 U.S. 54 (2016).
• U.S. Census Bureau, 2020 Census Table 1 (apportionment population and representatives by state).
• U.S. Census Bureau, 2020 P.L. 94-171 Redistricting Data (block populations) and TIGER/Line 2020 census block shapefiles.