How many Mary Frederick census records do you have?

We have 3053 US Census records for Mary Frederick, from 1900 to 1950, across 49 states and DC.

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

Yes. All Mary Frederick 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 Frederick?

We have Mary Frederick records from the 1900 through 1950 US Federal Census, across 49 states and DC. Use the year and state filters to narrow your results.

How do I find Mary Frederick 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 Frederick?

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 Frederick — US Census Records & Model Tree

We found 3053 free census records for Mary Frederick across 6 census years (1900–1950), in 49 states and DC and 755 counties. Each record includes our Model Tree — the same person linked across decades using machine learning, with per-link confidence scores.

Mary Frederick Census Records by State & County

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Showing of 3053 records for Mary Frederick US Census, ranked by Model Tree richness

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Year	Name	Age	Location	Birthplace	Occupation	Relation
1940	Mary A. Frederick	22	Duplin-County, North Carolina	North Carolina	Farm Laborer	Daughter
1930	Mary S. Frederick		Duplin, North Carolina	North Carolina	Laborer	Daughter
1910	Mary E Frederick		Linn, Kansas	Illinois	—	Wife
1940	Mary B Frederick	59	Hudson-County, New Jersey	Maine	—	Wife
1920	Mary Frederick		New York, New York	New York	Housewife	Head
1940	Mary Frederick	64	Macomb-County, Michigan	Michigan	—	Wife
1940	Mary Frederick	46	Norfolk-County, Massachusetts	Italy	—	Wife
1940	Mary Frederick	26	Wayne-County, Michigan	Michigan	—	Wife
1920	Mary E. Frederick		Passaic, New Jersey	New York	—	Head
1930	Mary Frederick		Wayne, Michigan	Poland	None	Wife
1900	Mary M Frederick	43	Passaic, New Jersey	New Jersey	—	Wife
1930	Mary N. Frederick		St Marys, Maryland	Maryland	—	Daughter
1920	Mary Frederick		St Martin, Louisiana	Louisiana	—	Daughter
1940	Mary Frederick	12	Middlesex-County, Massachusetts	Massachusetts	—	Daughter
1920	Mary M. Frederick		Montgomery, Pennsylvania	Pennsylvania	—	Daughter
1930	Mary E Frederick		Baltimore, Maryland	Maryland	—	Daughter
1940	Mary Frederick	11	Erie-County, Ohio	Ohio	School	Daughter
1940	Mary E. Frederick	40	Morgan-County, West Virginia	West Virginia	Seamstress	Wife
1930	Mary S Frederick		Knox, Ohio	Ohio	—	Wife
1930	Mary Frederick		Acadia, Louisiana	Louisiana	—	Daughter
1940	Mary Frederick	54	Washington-County, Pennsylvania	France	—	Wife
1930	Mary Frederick		Carbon, Pennsylvania	Pennsylvania	Winder	Daughter
1940	Mary Frederick	12	Lackawanna-County, Pennsylvania	Pennsylvania	—	Daughter
1920	Mary R. Frederick		None, Maryland	Maryland	Clerk	Daughter
1940	Mary @ Frederick	45	Waukesha-County, Wisconsin	Illinois	—	Wife
1920	Mary Louise Frederick		Ashtabula, Ohio	Ohio	—	Daughter
1940	Mary L Frederick	10	Hamilton-County, Ohio	Ohio	—	Daughter
1930	Mary Frederick		Vermilion, Louisiana	Louisiana	—	Daughter
1940	Mary Frederick	54	Mason-County, Kentucky	Kentucky	—	Wife
1930	Mary Frederick		Allegheny, Pennsylvania	Pennsylvania	None	Daughter

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About Mary Frederick US Census Records & Model Tree

We've indexed 3053 free, proprietary US Census records for Mary Frederick across 1900–1950, covering 49 states and DC: Alabama, Alaska, 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, 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 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 3053 US Census records for Mary Frederick, from 1900 to 1950, across 49 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 Frederick'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 Frederick 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 Frederick records from the 1900 through 1950 US Federal Census, across 49 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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