MK
Mary Kozlowski — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Delta-County, Michigan
Our Model Tree links this Mary Kozlowski across the 1930 and 1940 US Censuses in Delta-County, Michigan (XGBoost, ~Confirmed) — first a spouse (b.~1895), then head of a 6-person household.
Age 45
b. ~1895
Female
Spouse
Born: Poland
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Delta-County, Michigan |
| Surname | Kozlowski |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 45 |
| Marital Status | Married |
| Birthplace | Poland |
| 1935 Residence (City) | Bark River |
| 1935 Residence (County) | Delta |
| Naturalization Status | Alien |
| Additional Details | |
| Highest Grade | 0 |
| 1935 Residence | Same house |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
| Township / Ward | Bark River |
| Est. Birth Year | ~1895 |
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.
6 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Mary Kozlowski | Spouse | — | 45 | ~1895 |
| Henry Kozlowski | Son | — | 20 | ~1920 |
| Tony Kozlowski | Head | — | 48 | ~1892 |
| Stella Kozlowski | Daughter | — | 16 | ~1924 |
| Donald Kozlowski | Son | — | 9 | ~1931 |
| Stanley Kozlowski | Son | — | 18 | ~1922 |
Census Appearances
1930
Delta, Michigan
Spouse, age 35
Delta, Michigan · implied b. ~1895 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kozlowski |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 35 |
| Marital Status | Married |
| Birthplace | Poland |
| Naturalization Status | First papers filed |
| Year of Immigration | 1911 |
| Age at First Marriage | 23 |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Can Read/Write | Yes |
| Mother Tongue | Polish |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
1940
Delta-County, Michigan
Spouse, age 45
Delta-County, Michigan · implied b. ~1895 — 6 household members
| Surname | Kozlowski |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 45 |
| Marital Status | Married |
| Birthplace | Poland |
| 1935 Residence (City) | Bark River |
| 1935 Residence (County) | Delta |
| Naturalization Status | Alien |
| Highest Grade | 0 |
| 1935 Residence | Same house |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
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 Kozlowski across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
Mary Kozlowski
Spouse · 1940 · age 45 · b. ~1895 · Michigan
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Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Delta-County, Michigan
Open full size
1940 US Federal Census — Delta-County, Michigan
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01745-00061)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Norman Delle | 13 | Son | — | Michigan |
| 42 | Lorraine Delle | 11 | Daughter | — | Michigan |
| 43 | Adeline Delle | 9 | Daughter | — | Michigan |
| 44 | Martha Irley | 84 | Mother-in-law | — | Sweden |
| 45 | Joseph Wrenckowski | 64 | Head | Farming | Poland |
| 46 | Alexandra Wrenckowski | 62 | Wife | — | Poland |
| 47 | Edmund Wrenckowski | 21 | Son | Farming | Michigan |
| 48 | Joseph Nelson | 30 | Head | Farming | Michigan |
| 49 | Frank Nelson | 22 | Brother | Farming | Michigan |
| 50 | Francis Butryn | 29 | Head | Farming | Pennsylvania |
| 51 | Genevieve Butryn | 21 | Wife | — | Michigan |
| 52 | Janis Butryn | 3 | Daughter | — | Michigan |
| 53 | Robert Butryn | 1 | Son | — | Michigan |
| 54 | Tony Kozlowski | 48 | Head | Farming | Poland |
| 55 | Mary Kozlowski THIS PERSON | 45 | Wife | — | Poland |
| 56 | Henry Kozlowski | 20 | Son | Farming | New York |
| 57 | Stanley Kozlowski | 18 | Son | — | Michigan |
| 58 | Stella Kozlowski | 16 | Daughter | — | Michigan |
| 59 | Donald Kozlowski | 9 | Son | — | Michigan |
| 60 | Eugene Seymour | 43 | Head | — | Michigan |
| 61 | Peter Skybourn | 66 | Head | Farming | Canada-French |
| 62 | Eugene Skybourn | 59 | Wife | — | Canada-French |
| 63 | Louis Skybourn | 32 | Son | Farming | Michigan |
| 64 | Francis Skybourn | 21 | Son | Farming | Michigan |
| 65 | Charles Butrin | 53 | Head | Farming | Poland |
| 66 | Madeline Butrin | 50 | Wife | — | Poland |
| 67 | Joseph Butrin | 19 | Son | Farming | Michigan |
| 68 | Stanley Butrin | 17 | Son | — | Michigan |
| 69 | Stella Butrin | 15 | Daughter | — | Michigan |
| 70 | Helen Butrin | 12 | Daughter | — | Michigan |
| 71 | Victoria Butrin | 11 | Daughter | — | Michigan |
| 72 | Paul Jr. Levesque | 28 | Head | Farming | Michigan |
| 73 | Eileen Levesque | 24 | Wife | — | Illinois |
| 74 | Mildred Levesque | 4 | Daughter | — | Illinois |
| 75 | Paul J. Levesque | 2 | Son | — | Illinois |
| 76 | Robert Levesque | 1 | Son | — | Michigan |
| 77 | Stanley Wrenckowski | 52 | Head | Laborer | Poland |
| 78 | Helen Wrenckowski | 29 | Wife | — | Canada-French |
| 79 | Henry Wrenckowski | 9 | Son | — | Michigan |
| 80 | Lillie Wrenckowski | 2 | Daughter | — | Michigan |
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)