How many William Mahoney census records do you have?

We have 4282 US Census records for William Mahoney, from 1900 to 1950, across 50 states, DC, and 1 territory.

What's in a William Mahoney census record?

You'll see William'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 William Mahoney'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 William Mahoney census records free?

Yes. All William Mahoney 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 William Mahoney?

We have William Mahoney records from the 1900 through 1950 US Federal Census, across 50 states, DC, and 1 territory. Use the year and state filters to narrow your results.

How do I find William Mahoney 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 William Mahoney?

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.

William Mahoney — US Census Records & Model Tree

We found 4282 free census records for William Mahoney across 6 census years (1900–1950), in 50 states, DC, and 1 territory and 631 counties. Each record includes our Model Tree — the same person linked across decades using machine learning, with per-link confidence scores.

William Mahoney Census Records by State & County

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Showing of 4282 records for William Mahoney US Census, ranked by Model Tree richness

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Year	Name	Age	Location	Birthplace	Occupation	Relation
1940	William Mahoney	23	Essex-County, Massachusetts	Massachusetts	Laborer	Son
1940	William J. Mahoney	31	Suffolk-County, Massachusetts	Massachusetts	—	Son
1920	William H. Mahoney		Baltimore, Maryland	Maryland	—	Son
1940	William J. Mahoney	21	Middlesex-County, Massachusetts	Massachusetts	Transportation Clerk	Son
1940	William Mahoney	23	Worcester-County, Massachusetts	Massachusetts	Asst. Manager	Son
1940	William Mahoney	24	Bay-County, Michigan	Michigan	Clerk	Son
1930	William J. Mahoney		Middlesex, Massachusetts	Massachusetts	Switch Repair	Son
1940	William Mahoney	25	New-York-County, New York	New York	Elevator Operator	Son
1940	William Mahoney	21	Kings-County, New York	New York	Messenger	Son
1940	William G. Mahoney	28	Kings-County, New York	New York	Night Supervisor	Head
1930	William Mahoney		Kings, New York	New York	—	Head
1920	William E. Mahoney		Worcester, Massachusetts	Rhode Island	Linotyper	Head
1940	William Mahoney	63	Kings-County, New York	Ireland	Lieutenant	Head
1940	William J. Mahoney	71	Middlesex-County, Massachusetts	England	Signalman	Head
1910	William Mahoney		Calhoun, Iowa	Wisconsin	Merchant	Head
1930	William Mahoney		New York, New York	New York	Helper	Son
1930	William Jr. Mahoney		Cuyahoga, Ohio	Ohio	Racer	Son
1910	William Mahoney		New York, New York	Ireland	Plasterer	Head
1920	William Mahoney		Westmoreland, Pennsylvania	Pennsylvania	None	Son
1940	William F. Mahoney	12	Orange-County, New York	New York	—	Son
1930	William Mahoney		Kings, New York	New York	Clerk	Head
1930	William Mahoney		Lackawanna, Pennsylvania	Pennsylvania	—	Son
1930	William T Jr Mahoney		Suffolk, Massachusetts	Massachusetts	Stock Boy	Son
1930	William M. Mahoney		Bronx, New York	New York	Bond Clerk	Son
1930	William Mahoney		New York, New York	New York	Helper	Head
1930	William T Mahoney		Suffolk, Massachusetts	Massachusetts	Delivery Clerk	Head
1930	William Mahoney		New York, New York	New York	Helper	Son
1920	William Mahoney		Cayuga, New York	New York	Machinist Helper	Son
1930	William Mahoney		Wirt, West Virginia	West Virginia	—	Son
1930	William Mahoney		Middlesex, Massachusetts	Massachusetts	—	Son

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About William Mahoney US Census Records & Model Tree

We've indexed 4282 free, proprietary US Census records for William Mahoney across 1900–1950, covering 50 states, DC, and 1 territory: 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, Puerto Rico, 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 William 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 4282 US Census records for William Mahoney, from 1900 to 1950, across 50 states, DC, and 1 territory.
: You'll see William'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 William Mahoney'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 William Mahoney 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 William Mahoney records from the 1900 through 1950 US Federal Census, across 50 states, DC, and 1 territory. 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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