THE 1920 HOUSE
APPORTIONMENT SIMULATOR
A THOUGHT EXPERIMENT

What if there were No Cap,
HOW BIG WOULD THE HOUSE BE TODAY?

After the 1920 Census, the United States had an average of 241,864 people for every seat in the House of Representatives. Congress did not conduct a new apportionment following that census. The next apportionment, following the 1930 Census, fixed the House at 435 seats. This tool asks what representation could look like today if population growth had continued to produce additional representatives instead of being confined to a fixed House.

POPULATION BASIS
HOUSE SIZE AT SELECTED RATIO Population divided by selected representation ratio
CURRENT HOUSE SIZE 435 Fixed at 435 for apportionment since 1930
TOTAL POPULATION APPLIED 2020 Census apportionment population
CURRENT PEOPLE PER REPRESENTATIVE National average

WHO GAINED POWER UNDER THE CAP?

The House was fixed at 435 seats beginning with the apportionment following the 1930 Census. This map compares each state's 1930 apportionment with its representation following the 2020 Census.

STATE Select a state
1930 SEATS
2020 SEATS
NET CHANGE
Fewer representatives than 1930
Same number
More representatives than 1930
Not yet a state in 1930
How to read this map: No Cap red shows states that have fewer House seats following the 2020 Census than they received following the 1930 Census. Navy shows states that gained seats. Because the total remains 435, changes in population redistribute representation among states rather than expanding the House.

HOW MUCH HAS REPRESENTATION BEEN DILUTED?

The Census Bureau reports the average population represented by each House seat for every state and every apportionment. This map compares each state's official 1930 Census people-per-seat figure with its official 2020 Census figure.

STATE Select a state
PEOPLE PER REP — 1930
PEOPLE PER REP — 2020
RATIO INCREASE
BETTER REPRESENTED
LEAST REPRESENTED
Darker red = greater dilution. The darkest states have experienced the largest percentage increase in the Census Bureau's average population per House seat between the 1930 and 2020 apportionments. Alaska and Hawaii are gray because neither was a state during the 1930 apportionment.

STATE-BY-STATE COMPARISON

This table returns to the 1920-ratio thought experiment. The default ratio is the Census Bureau's national 1920 average of 241,864 people per House seat. Change the ratio above to test other House sizes. Click a column heading to sort.

STATE POPULATION CURRENT SEATS SIMULATED SEATS CHANGE PEOPLE PER REP — CURRENT
TOTAL 435

WHAT THIS SHOWS

In 1920, the Census Bureau reported an average of 241,864 people per House seat nationwide. Congress received the 1920 apportionment counts but did not reapportion the House following that census.

Following the 1930 Census, 435 seats were apportioned among the states. The Census Bureau reports an average of 280,675 people per seat nationally for that apportionment.

By the 2020 Census, the House still contained 435 apportioned seats, but the national average had risen to 761,169 people per seat.

That means population growth no longer automatically produces more representation in the House. Instead, states compete for shares of a fixed pool of seats. A state gaining representation generally requires another state to lose representation.

The simulator asks what happens if we reverse that assumption: instead of holding the House at 435, hold the people-per-representative ratio roughly constant and allow the House to grow with the country.

SOURCES + METHODOLOGY

Historical seats and historical average population per House seat are from the U.S. Census Bureau, “Historical Apportionment Data (1910–2020).”

Census Bureau national averages: 1920 — 241,864 people per seat; 1930 — 280,675 people per seat; 2020 — 761,169 people per seat.

The Census Bureau notes that Congress did not reapportion following the 1920 Census. The size of the House during the next apportionment, following the 1930 Census, was fixed at 435.

Alaska and Hawaii are excluded from the 1930 historical comparison because they had not yet become states.

The 2020 simulator uses Census apportionment population, which includes the resident population of the 50 states plus qualifying overseas federal personnel and dependents allocated to their home states. The District of Columbia is not included in House apportionment.

The optional 2024 mode uses later Census population estimates rather than the Historical Apportionment Data table. It is included as a current-population thought experiment and is not an official congressional apportionment.

View the U.S. Census Bureau Historical Apportionment Data

Paid for by Project No Cap. Not authorized by any candidate or candidate's committee.