How many Mary Cahill census records do you have?

We have 4479 US Census records for Mary Cahill, from 1900 to 1950, across 47 states and DC.

What's in a Mary Cahill census record?

You'll see Mary'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 Mary Cahill'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 Mary Cahill census records free?

Yes. All Mary Cahill 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 Mary Cahill?

We have Mary Cahill records from the 1900 through 1950 US Federal Census, across 47 states and DC. Use the year and state filters to narrow your results.

How do I find Mary Cahill 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 Mary Cahill?

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.

Mary Cahill — US Census Records & Model Tree

We found 4479 free census records for Mary Cahill across 6 census years (1900–1950), in 47 states and DC and 520 counties. Each record includes our Model Tree — the same person linked across decades using machine learning, with per-link confidence scores.

Mary Cahill Census Records by State & County

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Showing of 4479 records for Mary Cahill US Census, ranked by Model Tree richness

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Year	Name	Age	Location	Birthplace	Occupation	Relation
1940	Mary A. Cahill	27	Onondaga-County, New York	New York	Stenographer	Daughter
1920	Mary C Cahill		Merrimack, New Hampshire	New Hampshire	Stenographer	Daughter
1920	Mary E. Cahill		Middlesex, Massachusetts	Ireland	—	Head
1940	Mary J. Cahill	74	Essex-County, Massachusetts	Ireland	—	Head
1910	Mary Cahill		New York, New York	Ireland	—	Wife
1940	Mary A. Cahill	50	Bronx-County, New York	Ireland	—	Wife
1930	Mary C. Cahill		Daviess, Indiana	Indiana	Servant	Wife
1940	Mary Cahill	50	Cook-County, Illinois	Ireland	—	Wife
1930	Mary Cahill		New York, New York	Ireland	—	Head
1910	Mary Cahill		New York, New York	Ireland	—	Wife
1940	Mary A. Cahill	76	Norfolk-County, Massachusetts	Massachusetts	—	Head
1940	Mary Cahill	56	Essex-County, New Jersey	Ireland	Domestic	Head
1930	Mary Cahill		New York, New York	Ireland	—	Head
1940	Mary Cahill	15	Cerro-Gordo-County, Iowa	Iowa	—	Daughter
1940	Mary Cahill	43	Cook-County, Illinois	Free State Ireland	—	Wife
1910	Mary Cahill		Hillsborough, New Hampshire	New Hampshire	Clerk	Daughter
1940	Mary A. Cahill	36	Bronx-County, New York	Ireland	House	Wife
1910	Mary Cahill		Mercer, New Jersey	New Jersey	—	Wife
1940	Mary Cahill	48	New-York-County, New York	Irish Free State	—	Wife
1910	Mary Cahill		New York, New York	New York	—	Wife
1930	Mary E Cahill		Providence, Rhode Island	Rhode Island	—	Daughter
1930	Mary Cahill		New York, New York	Ireland	Waitress	Head
1940	Mary R Cahill	37	Orleans-County, Louisiana	Louisiana	—	Daughter
1940	Mary Cahill	16	Hudson-County, New Jersey	New York	—	Daughter
1910	Mary Cahill		New Haven, Connecticut	Rhode Island	—	Wife
1930	Mary E. Cahill		Monmouth, New Jersey	New Jersey	—	Wife
1940	Mary Cahill	12	Franklin-County, Massachusetts	Massachusetts	—	Daughter
1940	Mary Cahill	28	Rock-County, Wisconsin	Iowa	Operator	Daughter
1940	Mary Cahill	12	Suffolk-County, Massachusetts	Massachusetts	—	Daughter
1930	Mary Cahill		Hudson, New Jersey	Ireland	Housewife	Wife

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About Mary Cahill US Census Records & Model Tree

We've indexed 4479 free, proprietary US Census records for Mary Cahill across 1900–1950, covering 47 states and DC: Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, 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, 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 Mary 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 4479 US Census records for Mary Cahill, from 1900 to 1950, across 47 states and DC.
: You'll see Mary'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 Mary Cahill'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 Mary Cahill 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 Mary Cahill records from the 1900 through 1950 US Federal Census, across 47 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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