How many Mary Kozlowski census records do you have?

We have 2733 US Census records for Mary Kozlowski, from 1900 to 1950, across 32 states.

What's in a Mary Kozlowski 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 Kozlowski'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 Kozlowski census records free?

Yes. All Mary Kozlowski 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 Kozlowski?

We have Mary Kozlowski records from the 1900 through 1950 US Federal Census, across 32 states. Use the year and state filters to narrow your results.

How do I find Mary Kozlowski 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 Kozlowski?

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 Kozlowski — US Census Records & Model Tree

We found 2733 free census records for Mary Kozlowski across 6 census years (1900–1950), in 32 states and 163 counties. Each record includes our Model Tree — the same person linked across decades using machine learning, with per-link confidence scores.

Mary Kozlowski Census Records by State & County

Records per state:

Census Record Search

First Name

Middle Name

Last Name (Required)

Census Year

State

Birth Year

Year Range

Birthplace

Age From

Age To

Exact match: Name Location Year

Alternate First Names (comma-separated)

Alternate Last Names (comma-separated)

County

Sex

Marital Status

Race

Relationship to Head

Occupation

Census Page ID

Family Members (in same household)

Search Records

Showing of 2733 records for Mary Kozlowski US Census, ranked by Model Tree richness

No records match your filters.

Year	Name	Age	Location	Birthplace	Occupation	Relation
1940	Mary C Kozlowski	26	Wayne-County, Michigan	Michigan	0	Wife
1930	Mary Kozlowski		Erie, New York	Germany	None	Wife
1940	Mary Kozlowski	45	Westchester-County, New York	Lithuania	—	Wife
1930	Mary Kozlowski		Fairfield, Connecticut	Poland	—	Wife
1940	Mary Kozlowski	47	Erie-County, New York	Poland	—	Wife
1940	Mary Kozlowski	43	Cook-County, Illinois	Poland	—	Wife
1940	Mary Kozlowski	56	Kings-County, New York	Poland	—	Wife
1920	Mary Kozlowski		Erie, New York	New York	—	Daughter
1930	Mary Kozlowski		Cook, Illinois	Illinois	—	Daughter
1940	Mary Kozlowski	48	Middlesex-County, New Jersey	Poland	—	Wife
1940	Mary A. Kozlowski	46	Montgomery-County, Pennsylvania	Poland	—	Wife
1940	Mary Kozlowski	17	Baltimore-City-County, Maryland	Maryland	Packer	Daughter
1940	Mary Kozlowski	56	Wayne-County, Michigan	Poland	—	Wife
1940	Mary Kozlowski	22	Wayne-County, Michigan	Michigan	Cake Wrapper	Daughter
1930	Mary Kozlowski		Wayne, Michigan	Poland	—	Head
1940	Mary Kozlowski	32	Allegheny-County, Pennsylvania	Pennsylvania	—	Wife
1930	Mary Kozlowski		Cuyahoga, Ohio	Ohio	—	Daughter
1940	Mary Kozlowski	53	Wayne-County, Michigan	Poland	—	Wife
1940	Mary Kozlowski	45	Delta-County, Michigan	Poland	—	Wife
1940	Mary H. Kozlowski	37	Mercer-County, New Jersey	Poland	—	Wife
1940	Mary Kozlowski	50	Cook-County, Illinois	Poland	—	Wife
1940	Mary Kozlowski	13	Cook-County, Illinois	Illinois	—	Daughter
1920	Mary Kozlowski		Luzerne, Pennsylvania	Pennsylvania	None	Daughter
1940	Mary Kozlowski	55	Susquehanna-County, Pennsylvania	Poland	—	Wife
1940	Mary Kozlowski	43	Philadelphia-County, Pennsylvania	Poland	—	Wife
1940	Mary Kozlowski	19	Hudson-County, New Jersey	New Jersey	Waitress	Daughter
1940	Mary G. Kozlowski	21	Allegany-County, New York	New York	—	Daughter
1940	Mary Kozlowski	35	Wayne-County, Michigan	Poland	—	Wife
1940	Mary Kozlowski	55	Cook-County, Illinois	Germany	—	Wife
1940	Mary Kozlowski	42	Hudson-County, New Jersey	Poland	—	Wife

Load More Mary Kozlowski Census Records

About Mary Kozlowski US Census Records & Model Tree

We've indexed 2733 free, proprietary US Census records for Mary Kozlowski across 1900–1950, covering 32 states: Arkansas, California, Colorado, Connecticut, Delaware, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oregon, Pennsylvania, Rhode Island, Texas, Utah, Virginia, West Virginia, Wisconsin.

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 2733 US Census records for Mary Kozlowski, from 1900 to 1950, across 32 states.
: 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 Kozlowski'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 Kozlowski 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 Kozlowski records from the 1900 through 1950 US Federal Census, across 32 states. 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.

Other Kozlowski US Census Records

John Kozlowski

All Kozlowski census records →

Browse More Surnames

Knapp Knight Knox Koch Kovach Kowalski Kramer Krause Krueger Kruse Kuhn Lake

← Back to US Census Records