Indiana
992,196estimated residentsMarion County
Births minus deaths+5.9
per 1,000
Movement from abroad+6.9
per 1,000
Movement within the U.S.−10.8
per 1,000
The County Ledger
See how births, deaths, and movement changed each U.S. county.
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How to explore
A county grows or shrinks as people are born, die, arrive, and leave. The Census Bureau estimates each part once a year so the pieces can be compared.
Start with Marion County
Read its 2025 equation. Bars to the right add people to the estimate; bars to the left subtract people.
Change the year
Follow the five lines to see whether births, deaths, and movement kept playing the same roles.
Choose a county group
Separate counties by whether births or deaths were higher and whether movement within the United States was in or out.
Compare a similar size
Match two counties with similar 2025 populations and compare the different paths that brought them there.
- Population estimate
- A calculated count for a date between censuses, built from a population base plus estimated births, deaths, and movement.
- Rate per 1,000
- The estimated change for every 1,000 residents, which makes counties of different sizes easier to compare.
- Natural change
- Births minus deaths during the year; the interface writes this calculation out instead of using the term as a control label.
- Net movement
- Arrivals minus departures; a positive value means more arrivals, not that nobody left.
- Residual
- The balancing adjustment between the demographic pieces and the final population estimate.
United States · 2020–2025
The County
Ledger
See how births, deaths, and movement changed each U.S. county.
A county grows or shrinks as people are born, die, arrive, and leave. The Census Bureau estimates each part once a year.
01 / Follow one county
What changed Marion County in 2025?
Choose a county and year. Each rate is the estimated change for every 1,000 residents during the year. Bars to the right add people; bars to the left subtract people.
Marion County, Indiana992,196estimated residents on July 1, 2025
Change during the year+1,983+2.0 per 1,000 residents
Births minus deaths+5.9
14.6 births − 8.7 deaths per 1,000
Movement from abroad+6.9
Arrivals from abroad minus departures abroad, including U.S.-born people
Movement within the U.S.−10.8
Moves in from other U.S. counties minus moves out to them
Balancing adjustment0.0
The small remainder needed to make the estimates add up
+5.9 + +6.9 + −10.8 + 0.0≈ +2.0 people per 1,000
What to notice: Births exceeded deaths, while more people moved elsewhere in the United States than moved in. Movement numbers are net changes, not the total number of moves.
02 / Read five years
Did the mix stay the same?
Lines track each part of annual change for the selected county. The zero line separates additions from subtractions. Choosing a year above moves the marker here.
Total changeBirths minus deathsMovement from abroadMovement within the U.S.
2025+2.0 per 1,000
The county’s estimated population grew during this year.
03 / Compare every county
Which combinations were common in 2025?
Each dot is a county or county equivalent. Left and right compare births with deaths. Up and down compare moves within the United States. Choose a group to show it, then choose a county from the list.
More deaths ←→ More birthsMore U.S. arrivals ↑More U.S. departures ↓
Counties that stand out in this group
How to read it: Dot size follows population. The field clips extreme rates at its edges so the main pattern remains readable. The list keeps the exact rate.
04 / Match similar sizes
Could two similar-sized counties change differently?
Compare the selected county with one whose 2025 population is within 25 percent. If no county is that close in size, the control offers the nearest populations instead. Longer bars mean a larger rate.
Texas
781,194estimated residentsMontgomery County
Births minus deaths+5.3
per 1,000
Movement from abroad+4.5
per 1,000
Movement within the U.S.+29.6
per 1,000
What to notice: Marion County and Montgomery County had similar 2025 populations, but movement within the United States pushed their estimates in opposite directions.
How the estimates work and what they cannot show
The Census Bureau starts with a population base, then adds births, subtracts deaths, and adds net movement. It uses records from several public agencies and statistical methods to estimate the pieces. A residual balances small differences between the pieces and the final total.
These are annual estimates, not a count of every event or person. Domestic movement uses sources including tax returns and Medicare enrollment; movement from abroad uses several sources and proxy populations. The latest birth and death inputs can be provisional. Each new vintage revises the full series.
The data show how the published estimate was constructed. They do not explain why people moved, why births or deaths changed, how change was distributed within a county, or whether growth helped residents. County boundaries follow the Vintage 2025 geography.
Why this exists
The question
How did births, deaths, movement within the United States, and movement from abroad combine to change each county's population estimate from 2020 through 2025?
What to try
Start with Marion County's 2025 population equation, read its five-year change, compare all counties by births versus deaths and domestic movement, then match it with a similar-sized county whose mix differs.
Method and limits
About the data
I selected the U.S. Census Bureau Population Estimates Program's Vintage 2025 county totals and components file after checking the current county release page, its field layout, the January 2026 methodology statement, and the Census Bureau's open-data terms. The March 2026 release is the current completed vintage. I retrieved the 2,071,735-byte CSV on September 26, 2026 and pinned it to SHA-256 4f5a499d851e2cb48fd7a5405e5a9235453a8a66933657aacd10df0e264f35d5.
The reproducible Python reduction validates the source size, checksum, county summary level, and the expected 3,144 county and county-equivalent records. It retains the July 1 population estimate and annual population change count, plus birth, death, natural change, international movement, domestic movement, residual, and total-change rates for the complete July-to-June periods ending in 2021 through 2025. Rates are rounded to two decimal places only in the published snapshot. The page imports the 1,133,925-byte snapshot and makes no runtime network requests.
The Census Bureau calculates component rates by dividing the annual component by the average of the starting and ending July 1 populations, then multiplying by 1,000. I reproduce the residual and total-change rates from the published counts and population estimates. The four county groups use the sign of the published natural-change rate and the sign of net domestic movement. Similar-sized comparisons require 2025 populations within 25 percent, then rank the largest difference across births minus deaths, international movement, and domestic movement rates. If no other county meets the 25-percent band, the interface offers the 10 nearest populations, keeps the closest first, and labels the comparison as broad.
These are modeled estimates, not a direct count of every event or move. Domestic movement draws on sources including tax returns, Medicare enrollment, Social Security records, and group-quarters change. International movement uses several sources and proxy populations. Recent birth and death inputs can be provisional. A residual reconciles the demographic pieces with controlled totals. Each new vintage revises the full series, and Vintage 2025 uses January 1, 2025 geography. The record cannot explain why a component changed, show movement between specific county pairs, describe variation within a county, or establish whether growth improved people's lives.
Skills used
- Data analysis
- Data engineering
- Statistical reasoning
- Systems design
- Visualization
- Information design
- Interaction design
- Visual design
- Creative coding
- Product thinking
- Editorial storytelling
- Accessibility
- Performance
What the data shows
- In 2025, 1,384 of 3,144 counties and county equivalents had more deaths than births but gained people through movement from elsewhere in the United States. It was the largest of the four combinations shown in the county field.
- Marion County, Indiana gained an estimated 15,488 residents from July 2020 to July 2025. Births minus deaths added 24,764 and movement from abroad added 45,144, while movement to and from other U.S. counties subtracted 54,275; the residual subtracted 145.
- Harris County, Texas had the largest cumulative estimated population gain from 2021 through 2025 at 310,966. Los Angeles County, California had the largest loss at 301,576. County size, revised inputs, and the different components all matter when reading those totals.