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Mary Kowalski — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Suffolk-County, New York
Our Model Tree links this Mary Kowalski across the 1930 and 1940 US Censuses in Suffolk-County, New York (XGBoost, ~Confirmed) — first a daughter (b.~1898), then head of a 8-person household.
Age 42
b. ~1898
Female
Daughter
Born: Austria
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Suffolk-County, New York |
| Surname | Kowalski |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 42 |
| Marital Status | Single |
| Birthplace | Austria |
| 1935 Residence (City) | E. Setauket |
| 1935 Residence (County) | Suffolk |
| Naturalization Status | First papers filed |
| Additional Details | |
| Industry | 0 |
| Highest Grade | 0 |
| 1935 Residence | Same place |
| Birth Country | Austria |
| Birthplace (normalized) | austria |
| Township / Ward | E Setauket |
| Est. Birth Year | ~1898 |
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 Mary | Age | Birth yr |
|---|---|---|---|---|
| Steven Kowalski | Son | — | 17 | ~1923 |
| Mary Kowalski | Daughter | — | 14 | ~1926 |
| George Kowalski | Son | — | 12 | ~1928 |
| Frances Kowalski | Daughter | — | 9 | ~1931 |
| Mary Kowalski | Daughter | — | 42 | ~1898 |
| Mary Kowalski | Head | — | 56 | ~1884 |
| Felix Kowalski | Son | — | 10 | ~1930 |
| Sophie Kowalski | Daughter | — | 18 | ~1922 |
Census Appearances
1930
Kings, New …
Spouse, age 33
Kings, New York · implied b. ~1897 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 33 |
| Marital Status | Married |
| Birthplace | Austria |
| Naturalization Status | Naturalized |
| Year of Immigration | 1915 |
| Age at First Marriage | 17 |
| Father's Birthplace | Austria |
| Mother's Birthplace | Austria |
| Occupation | Operator |
| Industry | Dresses |
| Class of Worker | W |
| Can Read/Write | Yes |
| Mother Tongue | Yiddish |
| Birth Country | Austria |
| Birthplace (normalized) | austria |
1940
Suffolk-County, New …
Daughter, age 42
Suffolk-County, New York · implied b. ~1898 — 8 household members
| Surname | Kowalski |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 42 |
| Marital Status | Single |
| Birthplace | Austria |
| 1935 Residence (City) | E. Setauket |
| 1935 Residence (County) | Suffolk |
| Naturalization Status | First papers filed |
| Industry | 0 |
| Highest Grade | 0 |
| 1935 Residence | Same place |
| Birth Country | Austria |
| Birthplace (normalized) | austria |
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 Kowalski across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Kowalski
Daughter · 1940 · age 42 · b. ~1898 · New York
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Sibling
Sophie Kowalski
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Mary Kowalski
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
George Kowalski
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Steven Kowalski
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Felix Kowalski
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Frances Kowalski
Sibling · 1940 · age 9
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 — Suffolk-County, New York
Open full size
1940 US Federal Census — Suffolk-County, New York
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-02784-00580)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Roberta Vones | 5 | Head | — | New York |
| 2 | Jerry Vones | 3 | Son | — | New York |
| 3 | Morris O. Garnes | 33 | Head | Music Teacher | Connecticut |
| 4 | Ann Garnes | 3 | Daughter | — | Connecticut |
| 5 | Everett Jr. Hart | 1 | Son | — | New York |
| 6 | Everett Hart | 23 | Boarder | Laborer | New York |
| 7 | Michael Sacha | 50 | Head | Laborer | Poland |
| 8 | Paula Sacha | 58 | Wife | Laborer | Lithuania |
| 9 | Jacob Faraday | 33 | Head | Laborer | Virginia |
| 10 | Abie Faraday | 33 | Wife | — | Virginia |
| 11 | Shadow Faraday | 14 | Son | — | New York |
| 12 | Abie Faraday | 12 | Daughter | — | New York |
| 13 | Hazel Faraday | 10 | Daughter | — | New York |
| 14 | George Faraday | 7 | Son | — | New York |
| 15 | Eva Faraday | 6 | Daughter | — | New York |
| 16 | Hilda Faraday | 5 | Daughter | — | New York |
| 17 | Jacob Faraday | 1 | Son | — | New York |
| 18 | Henry O. Castor | 37 | Head | Caretaker | California |
| 19 | Nelva Castor | 34 | Wife | — | New York |
| 20 | Guy Jr. Castor | 7 | Son | — | New York |
| 21 | Simone Castor | 2 | Daughter | — | New York |
| 22 | John Bayles | 32 | Head | Superintendent | New York |
| 23 | Rose O. Bayles | 22 | Wife | — | New York |
| 24 | George P. Bayles | 1 | Son | — | New York |
| 25 | Mary Kowalski | 56 | Head | Handyman | Austria |
| 26 | Mary Kowalski THIS PERSON | 42 | Daughter | — | Austria |
| 27 | Sophie Kowalski | 18 | Daughter | — | New York |
| 28 | Steven Kowalski | 17 | Son | Farm Laborer | New York |
| 29 | Mary Kowalski | 14 | Daughter | — | New York |
| 30 | George Kowalski | 12 | Son | — | New York |
| 31 | Felix Kowalski | 10 | Son | — | New York |
| 32 | Frances Kowalski | 9 | Daughter | — | New York |
| 33 | William Hart | 47 | Head | Tree Surgeon | New York |
| 34 | Bertha V. Hart | 47 | Wife | — | New York |
| 35 | William Hart | 19 | Son | Truck Driver | New York |
| 36 | Warren Hart | 18 | Son | Tree Surgeon | New York |
| 37 | Raymond Hart | 7 | Son | — | New York |
| 38 | Roger Hart | 5 | Son | — | New York |
| 39 | Patricia Hart | 4 | Daughter | — | New York |
| 40 | Josephine Gwardowski | 56 | Head | — | Poland |
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)