How many John Koch census records do you have?

We have 4027 US Census records for John Koch, from 1900 to 1950, across 46 states and DC.

What's in a John Koch census record?

You'll see John's age, birthplace, occupation, and relationship to the head of household — plus everyone else who lived in the same home. For 1940 and 1950 records, you can also view the original handwritten census page.

How do I use census records for family research?

Census records are a snapshot of a family every 10 years. You can follow John Koch's household over time — see when children appear, when people move states, and who's living together. YourRoots connects census data with Tree Matching and AI tools so you can build out your tree faster.

Are John Koch census records free?

Yes. All John Koch census records on YourRoots are free to search and view — no subscription required. We built our own index from the original federal census images.

Which census years and states cover John Koch?

We have John Koch records from the 1900 through 1950 US Federal Census, across 46 states and DC. Use the year and state filters to narrow your results.

How do I find John Koch in the census?

Start by narrowing the year and state. If you know an approximate birth year, use the age column to match — census age minus the census year gives you a birth year estimate. Household members, birthplace, and occupation help confirm you have the right person.

What is the Model Tree for John Koch?

The Model Tree is YourRoots' unique feature that links a person across multiple census decades and reconstructs their likely family — parents, siblings, spouse, and children — based on household patterns. It turns isolated records into a connected family network.

Where does the census data come from?

All records originate from the US Federal Census microfilm digitized by NARA (National Archives and Records Administration). YourRoots re-indexed the original page images using modern AI, catching names and details that older transcriptions missed.

John Koch — US Census Records & Model Tree

We found 4027 free census records for John Koch across 6 census years (1900–1950), in 46 states and DC and 703 counties. Each record includes our Model Tree — the same person linked across decades using machine learning, with per-link confidence scores.

John Koch Census Records by State & County

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Showing of 4027 records for John Koch US Census, ranked by Model Tree richness

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Year	Name	Age	Location	Birthplace	Occupation	Relation
1930	John W. Koch		Lehigh, Pennsylvania	Pennsylvania	Bookkeeper	Son
1940	John Koch	61	Marshall-County, Kansas	Kansas	Laborer	Head
1940	John Koch	58	Wayne-County, Michigan	Germany	Moulder	Head
1940	John F. Koch,	57	Lehigh-County, Pennsylvania	New Jersey	Mail Operator	Head
1940	John Koch	52	Milwaukee-County, Wisconsin	Hungary	Crane Repair	Head
1940	John H. Koch	54	Mccone-County, Montana	Iowa	Farmer	Head
1940	John Koch	55	Cook-County, Illinois	Wisconsin	Machinist	Head
1940	John Koch	78	Scott-County, Iowa	Iowa	—	Head
1930	John M. Koch		Medina, Texas	Texas	—	Head
1940	John Jr Koch	30	Winnebago-County, Wisconsin	Wisconsin	Lumber Piler	Son
1940	John L. Koch	40	Dane-County, Wisconsin	Wisconsin	Farmer	Head
1910	John A. Koch		Antelope, Nebraska	Nebraska	None	Son
1910	John H Koch		Sarpy, Nebraska	Germany	Saloon Keeper	Head
1910	John Koch		Essex, New Jersey	New Jersey	Carpenter	Son
1940	John A. Koch	18	Ramsey-County, Minnesota	Minnesota	—	Son
1940	John P Koch	46	Clark-County, Washington	Massachusetts	Locomotive Fireman	Head
1930	John H Koch		Posey, Indiana	Indiana	Farmer	Head
1910	John Koch		Kings, New York	Germany	Retail Merchant	Head
1910	John Koch		Washington, Illinois	Illinois	Farmer	Head
1920	John Koch		St Clair, Illinois	Illinois	—	Son
1930	John Koch		Ashland, Wisconsin	Wisconsin	None	Son
1940	John Koch	45	Luzerne-County, Pennsylvania	Penna	Laborer	Head
1940	John Koch	53	Cloud-County, Kansas	Kansas	Farmer	Son
1940	John B. Koch	34	Logan-County, Arkansas	Arkansas	Farmer	Head
1920	John Koch		Whitman, Washington	Illinois	Farmer	Head
1920	John G. Koch		Northampton, Pennsylvania	Pennsylvania	Teacher	Head
1940	John Koch	35	Colorado-County, Texas	Texas	Laborer	Head
1910	John Koch		Fond Du Lac, Wisconsin	Wisconsin	Farm Laborer	Son
1940	John B. Koch	17	Bronx-County, New York	New York	—	Son
1920	John C Koch		Bremer, Iowa	Iowa	Farmer	Head

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About John Koch US Census Records & Model Tree

We've indexed 4027 free, proprietary US Census records for John Koch across 1900–1950, covering 46 states and DC: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, Wyoming.

Each record includes our Model Tree — a longitudinal reconstruction that links the same person across census decades using machine learning (XGBoost record linkage). Every link carries a confidence score: Verified (≥0.99), Confirmed (≥0.95), or Linked (lower confidence). This tells you not just what the census says, but how reliably we've connected records across time.

Every record also shows the full household — who John lived with, their ages, birthplaces, and occupations. For 1940 and 1950 records, you can view the original handwritten census page from the National Archives.

How we build the Model Tree. YourRoots independently indexes US Census records from NARA microfilm and links persons across decades using XGBoost-based record linkage. Each link's confidence is a per-pair match score from the model. Household corroboration (co-residents appearing on the same census pages in multiple years) strengthens the signal. The Model Tree is not a family tree submitted by users — it's reconstructed from the census data itself.

Last updated: July 30, 2026

Frequently Asked Questions

: We have 4027 US Census records for John Koch, from 1900 to 1950, across 46 states and DC.
: You'll see John's age, birthplace, occupation, and relationship to the head of household — plus everyone else who lived in the same home. For 1940 and 1950 records, you can also view the original handwritten census page.
: Census records are a snapshot of a family every 10 years. You can follow John Koch's household over time — see when children appear, when people move states, and who's living together. YourRoots connects census data with Tree Matching and AI tools so you can build out your tree faster.
: Yes. All John Koch census records on YourRoots are free to search and view — no subscription required. We built our own index from the original federal census images.
: We have John Koch records from the 1900 through 1950 US Federal Census, across 46 states and DC. Use the year and state filters above to narrow your results.
: Start by narrowing the year and state. If you know an approximate birth year, use the age column to match — census age minus the census year gives you a birth year estimate. Household members, birthplace, and occupation help confirm you have the right person.
: The Model Tree is YourRoots' unique feature that links a person across multiple census decades and reconstructs their likely family — parents, siblings, spouse, and children — based on household patterns. It turns isolated records into a connected family network.
: All records originate from the US Federal Census microfilm digitized by NARA (National Archives and Records Administration). YourRoots re-indexed the original page images using modern AI, catching names and details that older transcriptions missed.