How many William Knapp census records do you have?

We have 2853 US Census records for William Knapp, from 1900 to 1950, across 47 states and DC.

What's in a William Knapp 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 Knapp'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 Knapp census records free?

Yes. All William Knapp 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 Knapp?

We have William Knapp 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 William Knapp 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 Knapp?

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 Knapp — US Census Records & Model Tree

We found 2853 free census records for William Knapp across 6 census years (1900–1950), in 47 states and DC and 648 counties. Each record includes our Model Tree — the same person linked across decades using machine learning, with per-link confidence scores.

William Knapp Census Records by State & County

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Showing of 2853 records for William Knapp US Census, ranked by Model Tree richness

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Year	Name	Age	Location	Birthplace	Occupation	Relation
1940	William (X) Knapp	21	Marin-County, California	California	—	Son
1940	William Knapp	25	Queens-County, New York	New York	Office Helper	Son
1920	William Knapp		Mason, West Virginia	West Virginia	Farmer	Head
1920	William M. Knapp		Cuyahoga, Ohio	Pennsylvania	Salesman	Head
1930	William Knapp		Albany, New York	New York	Retired	Head
1920	William Knapp		Dane, Wisconsin	New York	Undertaker	Head
1940	William Knapp	15	Cayuga-County, New York	New York	New Worker	Son
1940	William A. Knapp	17	Jefferson-County, New York	New York	—	Son
1940	William Knapp	31	Mercer-County, New Jersey	New Jersey	Dust Presser	Head
1940	William Knapp	13	Mercer-County, New Jersey	New Jersey	—	Son
1930	William Knapp		Tazewell, Illinois	Germany	Farmer	Head
1930	William Jr. Knapp		Tazewell, Illinois	Illinois	—	Son
1920	William Jr Knapp		Camden, New Jersey	Pennsylvania	—	Son
1920	William Jr Knapp		Philadelphia, Pennsylvania	Pennsylvania	Apprentice	Son
1910	William Knapp		Otter Tail, Minnesota	Indiana	Carpenter	Head
1940	William B. Knapp	31	Jefferson-County, Pennsylvania	Pennsylvania	Laborer	Head
1940	William R. Knapp	25	Cherokee-County, Kansas	Kansas	Cook	Son
1940	William Knapp	12	Middlesex-County, New Jersey	New Jersey	—	Son
1940	William Knapp	16	Stone-County, Arkansas	Arkansas	Farm Laborer	Son
1920	William Knapp		St Clair, Illinois	Missouri	Stove Mounter	Son
1930	William H Knapp		Fairfield, Connecticut	New York	—	Head
1940	William Knapp	13	Price-County, Wisconsin	Wisconsin	—	Son
1940	William Knapp	13	Cook-County, Illinois	ILLINOIS	—	Son
1910	William L Knapp		Jefferson, Kansas	Kentucky	Engineer	Head
1940	William T Knapp	14	Vanderburgh-County, Indiana	Indiana	—	Son
1940	William Knapp	60	Benzie-County, Michigan	Michigan	Farm Hand	Head
1940	William S. Knapp	64	Monroe-County, Michigan	Michigan	Merchant	Head
1910	William E Knapp		Williams, Ohio	Ohio	Farmer	Head
1930	William Knapp		Lucas, Ohio	Ohio	—	Son
1940	William Knapp	11	Grundy-County, Illinois	Illinois	—	Son

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About William Knapp US Census Records & Model Tree

We've indexed 2853 free, proprietary US Census records for William Knapp across 1900–1950, covering 47 states and DC: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, District of Columbia, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, 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 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 2853 US Census records for William Knapp, from 1900 to 1950, across 47 states and DC.
: 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 Knapp'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 Knapp 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 Knapp 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.