LC
Lillian Cook — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Sonoma-County, California
Our Model Tree links this Lillian Cook across the 1930 and 1940 US Censuses in Sonoma-County, California (XGBoost, ~Confirmed) — first a daughter (b.~1930), then head of a 8-person household.
Age 10
b. ~1930
Female
Daughter
Born: California
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Sonoma-County, California |
| Surname | Cook |
| Given Name | Lillian |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 10 |
| Marital Status | Single |
| Birthplace | California |
| 1935 Residence (City) | Santa Rosa Township |
| 1935 Residence (County) | Sonoma |
| Additional Details | |
| Highest Grade | No 4 |
| 1935 Residence | Same place |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
| Township / Ward | Santa Rosa Township |
| Est. Birth Year | ~1930 |
Household Members
Census records only state relationship to the household head.
Pairwise kinship is derived (~90–95% accurate), not recorded.
Step/blended families and boarders can break it.
8 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Lillian | Age | Birth yr |
|---|---|---|---|---|
| Helen Cook | Daughter | — | 2 | ~1938 |
| Leon Cook | Son | — | 14 | ~1926 |
| Lillian Cook | Daughter | — | 10 | ~1930 |
| Gladys Cook | Daughter | — | 13 | ~1927 |
| May Cook | Daughter | — | 11 | ~1929 |
| Helen Cook | Spouse | — | 33 | ~1907 |
| Leon Cook | Head | — | 48 | ~1892 |
| Colleen Cook | Daughter | — | 8 | ~1932 |
Census Appearances
1930
Sonoma, California
Daughter, age
Sonoma, California · implied b. ~1930 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Cook |
| Given Name | Lillian M. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 0 |
| Marital Status | Single |
| Birthplace | California |
| Father's Birthplace | California |
| Mother's Birthplace | California |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
1940
Sonoma-County, California
Daughter, age 10
Sonoma-County, California · implied b. ~1930 — 8 household members
| Surname | Cook |
| Given Name | Lillian |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 10 |
| Marital Status | Single |
| Birthplace | California |
| 1935 Residence (City) | Santa Rosa Township |
| 1935 Residence (County) | Sonoma |
| Highest Grade | No 4 |
| 1935 Residence | Same place |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
Model Tree
An inferred pedigree reconstructed from census links — up to 4 generations within the 1900–1950 window. Closer generations are built from household co-residence; deeper ones are bridged by following a relative to their own childhood census. Confidence compounds and weakens with each generation.
Our Model Tree links Lillian Cook across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Lillian Cook
Daughter · 1940 · age 10 · b. ~1930 · California
★ You are viewing this record
Sibling
May Cook
Sibling · 1940 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Leon Cook
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Helen Cook
Sibling · 1940 · age 2
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Gladys Cook
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Colleen Cook
Sibling · 1940 · age 8
Source co-child of head (derived)
● Co-child · derived · ~0.88
Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Sonoma-County, California
Open full size
1940 US Federal Census — Sonoma-County, California
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00350-00471)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Cora Williams | 58 | Mother-in-law | Attendant | California |
| 42 | Elsie Williams | 24 | Sister-in-law | General Labor | California |
| 43 | Edward Williams | 20 | Brother-in-law | New Worker | California |
| 44 | Rudolf F. Danhausen | 38 | Head | Truck Driver | California |
| 45 | Therese E. Danhausen | 42 | Wife | — | Michigan |
| 46 | John Stewart | 51 | Hired hand | General Labor | England |
| 47 | Ollie M. Becker | 61 | Head | Proprietor | Iowa |
| 48 | Harold Y. Becker | 40 | Son | Upholsterer | Nebraska |
| 49 | Dottie E. Smithy | 32 | Head | General Labor | Oklahoma |
| 50 | Ollie S. Smithy | 25 | Brother | General Labor | Oklahoma |
| 51 | Edith G. Fechter | 36 | Head | Farmer | California |
| 52 | Edith M. Fechter | 15 | daughter | — | California |
| 53 | Evelyn S. Fechter | 14 | daughter | — | California |
| 54 | Barbara J. Fechter | 12 | daughter | — | California |
| 55 | John H. Fechter | 10 | son | — | California |
| 56 | Herbert Fechter | 28 | Brother-in-law | Farmer | California |
| 57 | George Fechter | 70 | Head | Farmer | Kansas |
| 58 | Sara S. Fechter | 62 | wife | — | New York |
| 59 | Raymond Fechter | 44 | Head | Farmer | California |
| 60 | Mildred M. Fechter | 37 | wife | — | California |
| 61 | Raymond Jr. Fechter | 17 | son | — | California |
| 62 | Ruby E. Fechter | 16 | daughter | — | California |
| 63 | Everett J. Fechter | 14 | son | — | California |
| 64 | Milton Fechter | 6 | son | — | California |
| 65 | Carol Ann Fechter | 3 | daughter | — | California |
| 66 | Antonio Malugani | 44 | Head | Farm Labor | Italy |
| 67 | Grace Malugani | 32 | wife | — | California |
| 68 | Henry T. Jarboe | 65 | Head | Farmer | Kansas |
| 69 | Carl Meyer | 51 | Head | Farmer | Germany |
| 70 | Frieda Meyer | 44 | wife | — | Germany |
| 71 | Elfriede Meyer | 9 | daughter | — | California |
| 72 | Leon F. Cook | 48 | Head | Farmer | California |
| 73 | Helen Cook | 33 | wife | — | California |
| 74 | Leon F. Jr. Cook | 14 | son | — | California |
| 75 | Gladys Cook | 13 | daughter | — | California |
| 76 | May Cook | 11 | daughter | — | California |
| 77 | Lillian Cook THIS PERSON | 10 | daughter | — | California |
| 78 | Colleen Cook | 8 | daughter | — | California |
| 79 | Helen Mary Cook | 2 | daughter | — | California |
| 80 | Marie H. Fahden | 67 | Head | — | Germany |
Related Census Records
About This Record & Model Tree
This record was independently indexed by YourRoots from the 1940 United States Federal Census (NARA). Our Model Tree links this person across census decades using XGBoost-based record linkage, with per-link confidence scores. Household corroboration strengthens the signal when co-residents appear on the same census pages in multiple years.
Source: National Archives and Records Administration (NARA)