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Mary Byrne — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Contra-Costa-County, California
Our Model Tree links this Mary Byrne across the 1930 and 1940 US Censuses in Contra-Costa-County, California (XGBoost, ~Confirmed) — first a daughter (b.~1920), then head of a 27-person household.
Age 20
b. ~1920
Female
Daughter
Born: California
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Contra-Costa-County, California |
| Surname | Byrne |
| Given Name | Mary A |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 20 |
| Marital Status | Single |
| Birthplace | California |
| 1935 Residence (City) | Jud TWP 7 |
| 1935 Residence (County) | Contra Costa |
| Additional Details | |
| Occupation | Checker |
| Industry | Cleaning & Dyeing |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 1092 |
| Highest Grade | H 4 |
| 1935 Residence | Same place |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
| Occupation | Checker |
| Township / Ward | Jud Twp 7 |
| Est. Birth Year | ~1920 |
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.
27 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Susan Foster | Daughter | — | 3 | ~1937 |
| Patricia Byrne | Daughter | — | 14 | ~1926 |
| Mary Byrne | Daughter | — | 20 | ~1920 |
| Virginia Hansen | Daughter | — | 10 | ~1930 |
| Josephine Byrne | Daughter | — | 24 | ~1916 |
| Mammie Culbertson | Other | — | 71 | ~1869 |
| Janet Hammond | Other | — | 79 | ~1861 |
| Hubert Hansen | Son | — | 12 | ~1928 |
| Harry Whitcomb | Son | — | 9 | ~1931 |
| Herbert Foster | Son | — | 5 | ~1935 |
| Arthur Ingersoll | Son | — | 2 | ~1938 |
| Carl Anderson | Son | — | 24 | ~1916 |
| Lyle Whitcomb | Son | — | 2 | ~1938 |
| Ruth Hansen | Spouse | — | 41 | ~1899 |
| Ester Anderson | Spouse | — | 59 | ~1881 |
| Doris Foster | Spouse | — | 32 | ~1908 |
| Claude Hansen | Spouse | — | 41 | ~1899 |
| Patrick Byrne | Spouse | — | 55 | ~1885 |
| Ernest Brooks | Spouse | — | 51 | ~1889 |
| Delia Byrne | Spouse | — | 49 | ~1891 |
| Maxine Ingersoll | Spouse | — | 28 | ~1912 |
| Thayer Whitcomb | Spouse | — | 38 | ~1902 |
| Herbert Foster | Spouse | — | 31 | ~1909 |
| Carl Anderson | Spouse | — | 64 | ~1876 |
| Irene Whitcomb | Spouse | — | 36 | ~1904 |
| Charlotte Brooks | Spouse | — | 41 | ~1899 |
| Arthur Ingersoll | Spouse | — | 29 | ~1911 |
Census Appearances
1930
Alameda, California
Daughter, age 10
Alameda, California · implied b. ~1920 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Byrne |
| Given Name | Maryalice |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 10 |
| Marital Status | Single |
| Birthplace | California |
| Father's Birthplace | Irish Free State |
| Mother's Birthplace | Irish Free State |
| Can Read/Write | Yes |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
1940
Contra-Costa-County, California
Daughter, age 20
Contra-Costa-County, California · implied b. ~1920 — 27 household members
| Surname | Byrne |
| Given Name | Mary A |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 20 |
| Marital Status | Single |
| Birthplace | California |
| 1935 Residence (City) | Jud TWP 7 |
| 1935 Residence (County) | Contra Costa |
| Occupation | Checker |
| Industry | Cleaning & Dyeing |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 1092 |
| Highest Grade | H 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 Mary Byrne across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Byrne
Daughter · 1940 · age 20 · b. ~1920 · California
★ You are viewing this record
Sibling
Arthur Ingersoll
Sibling · 1940 · age 2
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Patricia Byrne
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Josephine Byrne
Sibling · 1940 · age 24
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Virginia Hansen
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Harry Whitcomb
Sibling · 1940 · age 9
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Susan Foster
Sibling · 1940 · age 3
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Carl Anderson
Sibling · 1940 · age 24
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Herbert Foster
Sibling · 1940 · age 5
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Hubert Hansen
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Lyle Whitcomb
Sibling · 1940 · age 2
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 — Contra-Costa-County, California
Open full size
1940 US Federal Census — Contra-Costa-County, California
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00196-00555)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Thayer H Whitcomb | 38 | Husband | Chemical Engineer | Montana |
| 2 | Irene H Whitcomb | 36 | Wife | — | Kansas |
| 3 | Harry W Whitcomb | 9 | Son | — | California |
| 4 | Lyle T Whitcomb | 2 | Son | — | California |
| 5 | Janet B Hammond | 79 | Mother | — | Iowa |
| 6 | Arthur B Ingersoll | 29 | Husband | Sales Rep | New Zealand |
| 7 | Maxine E Ingersoll | 28 | Wife | — | California |
| 8 | Arthur Jr Ingersoll | 2 | Son | — | California |
| 9 | Herbert B Foster | 31 | Husband | Sanitary Engineer | California |
| 10 | Doris R Foster | 32 | Wife | — | California |
| 11 | Herbert D Foster | 5 | Son | — | California |
| 12 | Susan J Foster | 3 | Daughter | — | California |
| 13 | Patrick J Byrne | 55 | Husband | Dyer | Irish Free State |
| 14 | Delia Byrne | 49 | Wife | — | Irish Free State |
| 15 | Josephine Byrne | 24 | Daughter | Checker | California |
| 16 | Mary A Byrne THIS PERSON | 20 | Daughter | Checker | California |
| 17 | Patricia Byrne | 14 | Daughter | — | California |
| 18 | Claude H Hansen | 41 | Husband | Electric Machinist | Kansas |
| 19 | Ruth D Hansen | 41 | Wife | — | Oregon |
| 20 | Hubert C Hansen | 12 | Son | — | California |
| 21 | Virginia L Hansen | 10 | Daughter | — | California |
| 22 | Mammie H Culbertson | 71 | Mother | — | California |
| 23 | Ernest D Brooks | 51 | Husband | Store Keeper | Canada |
| 24 | Charlotte Brooks | 41 | Wife | — | Minnesota |
| 25 | Carl P Anderson | 64 | Husband | — | Sweden |
| 26 | Ester C Anderson | 59 | Wife | — | Sweden |
| 27 | Carl R Anderson | 24 | Son | House Carpenter | California |
| 28 | Ruth H Pickering | 53 | Head | — | Colorado |
| 29 | Julia M Pickering | 15 | Daughter | — | California |
| 30 | Elmer E Rinstein | 41 | Lodger | Sugar Worker | California |
| 31 | Stanley Pystel | 40 | Husband | Pipe Line Galvanizer | Poland |
| 32 | Julia Pystel | 36 | Wife | — | Pennsylvania |
| 33 | Leon P Pystel | 16 | Son | — | Pennsylvania |
| 34 | Chas A Bishops | 65 | Husband | Mechanical Engineer | Iowa |
| 35 | Margaret E Bishops | 58 | Wife | — | Iowa |
| 36 | Margaret A Sturm | 35 | Daughter | — | California |
| 37 | Clarence H Sturm | 33 | Son-in-law | Accountant | California |
| 38 | Alice Boyd | 56 | Head | — | Wisconsin |
| 39 | Clara L Murdock | 54 | Roomer | Clothing Saleswoman | New York |
| 40 | Earl W Smith | 31 | Head | Builder | Washington |
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)