How many Mary Decker census records do you have?

We have 3999 US Census records for Mary Decker, from 1900 to 1950, across 49 states and DC.

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

Yes. All Mary Decker 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 Decker?

We have Mary Decker 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 Decker 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 Decker?

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 Decker — US Census Records & Model Tree

We found 3999 free census records for Mary Decker across 6 census years (1900–1950), in 49 states and DC and 862 counties. Each record includes our Model Tree — the same person linked across decades using machine learning, with per-link confidence scores.

Mary Decker Census Records by State & County

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Showing of 3999 records for Mary Decker US Census, ranked by Model Tree richness

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Year	Name	Age	Location	Birthplace	Occupation	Relation
1920	Mary B. Decker		Ohio, Kentucky	Kentucky	None	Wife
1910	Mary N. Decker		Union, New Jersey	Pennsylvania	—	Wife
1940	Mary Decker	63	Lake-County, Illinois	Holland	—	Wife
1940	Mary A. Decker	65	St.-Louis-City-County, Missouri	Missouri	—	Wife
1940	Mary A. Decker	37	Columbia-County, New York	New York	—	Wife
1940	Mary Decker	43	Union-County, Kentucky	Kentucky	—	Wife
1940	Mary E. Decker	20	Union-County, Kentucky	Kentucky	Child Nurse	Daughter
1940	Mary S. Decker	13	Grayson-County, Kentucky	Kentucky	—	Daughter
1920	Mary A. Decker		Bureau, Illinois	Illinois	—	Daughter
1930	Mary Decker		Grayson, Kentucky	Kentucky	—	Wife
1930	Mary R. Decker		Wayne, Indiana	Indiana	Burner	Daughter
1920	Mary Decker		Susquehanna, Pennsylvania	Pennsylvania	Bookkeeper	Daughter
1940	Mary E. Decker	14	Jackson-County, Missouri	Missouri	—	Daughter
1940	Mary Decker	13	Monroe-County, New York	New York	—	Daughter
1910	Mary Decker		Mitchell, Iowa	Wisconsin	—	Wife
1940	Mary Decker	18	Salt-Lake-County, Utah	Utah	—	Daughter
1940	Mary G Decker	11	Pulaski-County, Missouri	Missouri	—	Daughter
1940	Mary Decker	50	Franklin-County, New York	New York	—	Wife
1910	Mary Decker		Pulaski, Missouri	Missouri	—	Wife
1900	Mary Decker	31	Camp, Texas	Mississippi	Housekeeper	Wife
1940	Mary Jane Decker	11	Kent-County, Michigan	Michigan	—	Daughter
1940	Mary Decker	20	Hudson-County, New Jersey	New Jersey	Stenographer	Daughter
1940	Mary Decker	11	Baltimore-City-County, Maryland	Maryland	—	Daughter
1940	Mary Decker	14	Hudson-County, New Jersey	New Jersey	—	Daughter
1940	Mary X Decker	44	Essex-County, New Jersey	New Jersey	Saleswoman	Head
1910	Mary Decker		Lancaster, Pennsylvania	Pennsylvania	—	Wife
1940	Mary Decker	19	Essex-County, New Jersey	New Jersey	Policy Writer	Daughter
1940	Mary Decker	45	Wayne-County, Michigan	Michigan	—	Wife
1940	Mary Decker	49	Hamilton-County, Ohio	Ohio	—	Wife
1930	Mary Decker		Ulster, New York	New York	Seamstress	Wife

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About Mary Decker US Census Records & Model Tree

We've indexed 3999 free, proprietary US Census records for Mary Decker across 1900–1950, covering 49 states and DC: Alabama, 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 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 3999 US Census records for Mary Decker, 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 Decker'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 Decker 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 Decker 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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