How many John Callahan census records do you have?

We have 9145 US Census records for John Callahan, from 1900 to 1950, across 50 states and DC.

What's in a John Callahan 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 Callahan'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 Callahan census records free?

Yes. All John Callahan 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 Callahan?

We have John Callahan records from the 1900 through 1950 US Federal Census, across 50 states and DC. Use the year and state filters to narrow your results.

How do I find John Callahan 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 Callahan?

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 Callahan — US Census Records & Model Tree

We found 9145 free census records for John Callahan across 6 census years (1900–1950), in 50 states and DC and 1011 counties. Each record includes our Model Tree — the same person linked across decades using machine learning, with per-link confidence scores.

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Showing of 9145 records for John Callahan US Census, ranked by Model Tree richness

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Year	Name	Age	Location	Birthplace	Occupation	Relation
1920	John J. Callahan		Grafton, New Hampshire	New Hampshire	Clerk	Son
1940	John Callahan	42	Essex-County, New Jersey	New Jersey	Foreman Label	Head
1930	John J Callahan		Campbell, Kentucky	Ohio	Clerk	Son
1930	John J. Callahan		Dubuque, Iowa	Iowa	Polisher	Son
1940	John A. Callahan	33	Knox-County, Kentucky	Kentucky	Laborer	Son
1940	John Callahan	46	Garfield-County, Oklahoma	Missouri	Farmer	Son
1940	John H. Callahan	29	Fulton-County, Georgia	Georgia	Salesman	Head
1940	John H. Callahan	24	Middlesex-County, Massachusetts	Massachusetts	Embosser	Head
1930	John Callahan		Essex, Massachusetts	Massachusetts	Laborer	Son
1940	John J. Callahan	35	Saratoga-County, New York	New York	Farmer	Son
1930	John J Callahan		Camden, New Jersey	New Jersey	Embosser	Son
1920	John Callahan		Kings, New York	Ireland	Manager	Head
1940	John Callahan	68	Bronx-County, New York	Ireland	Ticket Agent	Head
1940	John L. Callahan	41	Orleans-County, Vermont	New Hampshire	Inspector	Head
1940	John Callahan	59	Allen-County, Ohio	Ohio	Boilermaker Helper	Head
1920	John Callahan		New York, New York	Ireland	Porter	Head
1920	John Callahan		Middlesex, Massachusetts	Ireland	—	Head
1940	John Callahan	74	Middlesex-County, Massachusetts	Ireland	—	Head
1920	John Callahan		Hale, Texas	Texas	Farmer	Head
1920	John Callahan		Middlesex, Massachusetts	Ireland	—	Head
1920	John Callahan		Montgomery, Pennsylvania	Ireland	Laborer	Head
1940	John Callahan	18	Cook-County, Illinois	Michigan	—	Son
1910	John Callahan		Middlesex, Massachusetts	Massachusetts	Laborer	Head
1900	John Callahan	50	Fillmore, Minnesota	Ireland	Laborer (Day)	Head
1930	John Callahan		Dakota, Minnesota	Minnesota	Chauffeur	Son
1930	John J. Callahan		Cerro Gordo, Iowa	Iowa	—	Son
1940	John Callahan	26	Philadelphia-County, Pennsylvania	Penna	Laborer	Son
1940	John Callahan	12	Baltimore-County, Maryland	Maryland	—	Son
1910	John Callahan		Greene, Georgia	Georgia	Farm Laborer	Son
1910	John Callahan		Dubuque, Iowa	Iowa	Stock Seller	Head

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About John Callahan US Census Records & Model Tree

We've indexed 9145 free, proprietary US Census records for John Callahan across 1900–1950, covering 50 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, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, 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 9145 US Census records for John Callahan, from 1900 to 1950, across 50 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 Callahan'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 Callahan 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 Callahan records from the 1900 through 1950 US Federal Census, across 50 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.

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