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Mary Kowalski — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Erie-County, New York
Our Model Tree links this Mary Kowalski across the 1920, 1930 and 1940 US Censuses in Erie-County, New York (XGBoost, ~Confirmed) — first a spouse (b.~1899), then head of a 4-person household.
Age 41
b. ~1899
Female
Spouse
Born: New York
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Erie-County, New York |
| Surname | Kowalski |
| Given Name | Mary |
| Relationship to Head | wife |
| Sex | F |
| Color / Race | White |
| Age | 41 |
| Marital Status | Married |
| Birthplace | New York |
| 1935 Residence (City) | Buffalo city |
| 1935 Residence (County) | Erie |
| Additional Details | |
| Industry | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
| Township / Ward | Buffalo City |
| Est. Birth Year | ~1899 |
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.
4 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Mary Kowalski | Spouse | — | 41 | ~1899 |
| Robert Kowalski | Son | — | 15 | ~1925 |
| George Kowalski | Head | — | 50 | ~1890 |
| Louis Koch | Other | — | 19 | ~1921 |
Census Appearances
1920
Erie, New …
Other, age 21
Erie, New York · implied b. ~1899 — 50 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | Mary |
| Relationship to Head | Boarder |
| Sex | F |
| Color / Race | White |
| Age | 21 |
| Marital Status | Married |
| Birthplace | New York |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
1930
Erie, New …
Other, age 31
Erie, New York · implied b. ~1899 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | Mary |
| Relationship to Head | Wife-H |
| Sex | F |
| Color / Race | White |
| Age | 31 |
| Marital Status | Married |
| Birthplace | New York |
| Age at First Marriage | 21 |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Occupation | none |
| Can Read/Write | Yes |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
1940
Erie-County, New …
Spouse, age 41
Erie-County, New York · implied b. ~1899 — 4 household members
| Surname | Kowalski |
| Given Name | Mary |
| Relationship to Head | wife |
| Sex | F |
| Color / Race | White |
| Age | 41 |
| Marital Status | Married |
| Birthplace | New York |
| 1935 Residence (City) | Buffalo city |
| 1935 Residence (County) | Erie |
| Industry | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
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 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
Mary Kowalski
Spouse · 1940 · age 41 · b. ~1899 · New York
★ You are viewing this record
Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Erie-County, New York
Open full size
1940 US Federal Census — Erie-County, New York
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-02837-00189)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Rosalia Kolak | 19 | daughter | House Maid | New York |
| 42 | Francis Kolak | 10 | son | — | New York |
| 43 | Casper Kendron | 56 | head | Moulder | Austria |
| 44 | Sophia Kendron | 52 | wife | — | Austria |
| 45 | Florence Kendron | 17 | daughter | — | New York |
| 46 | Frank Jakubyak | 73 | head | — | Poland |
| 47 | William Jakubyak | 29 | son | Musician | New York |
| 48 | Theodore Szypanik | 36 | son-in-law | Pharmacist | New York |
| 49 | Gertrude Szypanik | 35 | daughter | — | New York |
| 50 | George Kowalski | 50 | head | Labourer | Poland |
| 51 | Mary Kowalski THIS PERSON | 41 | wife | — | New York |
| 52 | Robert Kowalski | 15 | son | New Worker | New York |
| 53 | Louis Koch | 19 | lodger | Meter Reader | New York |
| 54 | Frank Popowski | 50 | head | Coremaker | Poland |
| 55 | Antoinette Popowski | 48 | wife | — | Poland |
| 56 | Mary Popowski | 21 | daughter | Labourer | New York |
| 57 | Raymond Popowski | 20 | son | Labourer | New York |
| 58 | Dorothy Popowski | 11 | daughter | — | New York |
| 59 | Joseph Borzyck | 46 | head | Labourer | Poland |
| 60 | Madgeline Borzyck | 53 | wife | — | Poland |
| 61 | Stanley Kwietniewski | 20 | son | Assembler | Poland |
| 62 | Joseph Borzyck | 13 | son | — | New York |
| 63 | John Borzyck | 10 | son | — | New York |
| 64 | Stanley Grochowski | 51 | head | — | Poland |
| 65 | Sophie Grochowski | 53 | wife | — | Poland |
| 66 | Stephen Jasinski | 28 | head | Baker | Poland |
| 67 | Carrie Jasinski | 24 | wife | — | New York |
| 68 | Patrick Jasinski | 3 | son | — | New York |
| 69 | Valentine Grzybowski | 53 | head | Labourer | Poland |
| 70 | Agnes Grzybowski | 51 | wife | — | Poland |
| 71 | Valentine Jr. Grzybowski | 16 | son | — | New York |
| 72 | Edward Szemarj | 40 | head | Handy Man | Poland |
| 73 | Anna Szemarj | 32 | wife | Power Maid | Poland |
| 74 | Edward Jr. Szemarj | 5 | son | — | New York |
| 75 | Joseph Zieziula | 25 | lodger | Cook'S Helper | New York |
| 76 | Joseph Oleszak | 50 | head | Coremaker | Poland |
| 77 | Josephine Oleszak | 49 | wife | — | Poland |
| 78 | Helen Oleszak | 24 | daughter | Assembler | New York |
| 79 | Chester Oleszak | 22 | son | Machinist | New York |
| 80 | Harvey Oleszak | 20 | son | New Worker | New York |
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)