MK
Mary Kozlowski — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Allegheny-County, Pennsylvania
Our Model Tree links this Mary Kozlowski across the 1930 and 1940 US Censuses in Allegheny-County, Pennsylvania (XGBoost, ~Confirmed) — first a spouse (b.~1908), then head of a 7-person household.
Age 32
b. ~1908
Female
Spouse
Born: Pennsylvania
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Allegheny-County, Pennsylvania |
| Surname | Kozlowski |
| Given Name | Mary |
| Relationship to Head | wife |
| Sex | F |
| Color / Race | White |
| Age | 32 |
| Marital Status | Married |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | Sharpsburg Borough |
| 1935 Residence (County) | Allegheny |
| Additional Details | |
| Highest Grade | No 7 |
| 1935 Residence | Same place |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
| Township / Ward | Sharpsburg Borough |
| Est. Birth Year | ~1908 |
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.
7 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Theresa Kozlowski | Daughter | — | 3 | ~1937 |
| Mary Kozlowski | Spouse | — | 32 | ~1908 |
| John Kozlowski | Son | — | 5 | ~1935 |
| Martin Kozlowski | Head | — | 42 | ~1898 |
| Dorothy Kozlowski | Daughter | — | 11 | ~1929 |
| Florence Kozlowski | Daughter | — | 15 | ~1925 |
| Martin Kozlowski | Son | — | 13 | ~1927 |
Census Appearances
1930
Allegheny, Pennsylvania
Other, age 22
Allegheny, Pennsylvania · implied b. ~1908 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kazlowsky |
| Given Name | Martha |
| Relationship to Head | Wife-H |
| Sex | F |
| Color / Race | White |
| Age | 22 |
| Marital Status | Married |
| Birthplace | Pennsylvania |
| Age at First Marriage | 15 |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Can Read/Write | Yes |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1940
Allegheny-County, Pennsylvania
Spouse, age 32
Allegheny-County, Pennsylvania · implied b. ~1908 — 7 household members
| Surname | Kozlowski |
| Given Name | Mary |
| Relationship to Head | wife |
| Sex | F |
| Color / Race | White |
| Age | 32 |
| Marital Status | Married |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | Sharpsburg Borough |
| 1935 Residence (County) | Allegheny |
| Highest Grade | No 7 |
| 1935 Residence | Same place |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
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 32 · b. ~1908 · Pennsylvania
★ 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 — Allegheny-County, Pennsylvania
Open full size
1940 US Federal Census — Allegheny-County, Pennsylvania
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03417-00476)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Theresa Kocher | 9 | daughter | — | Pennsylvania |
| 2 | Dorothy Kocher | 6 | daughter | — | Pennsylvania |
| 3 | Robert Kocher | 3 | son | — | Pennsylvania |
| 4 | Lulu Helder | 56 | head | — | New York |
| 5 | Rosemarie Helder | 17 | daughter | Office Assistant | Pennsylvania |
| 6 | Martin Kozlowski | 42 | head | Bolt Maker | Pennsylvania |
| 7 | Mary Kozlowski THIS PERSON | 32 | wife | — | Pennsylvania |
| 8 | Florence Kozlowski | 15 | daughter | — | Pennsylvania |
| 9 | Martin Jr. Kozlowski | 13 | son | — | Pennsylvania |
| 10 | Dorothy Kozlowski | 11 | daughter | — | Pennsylvania |
| 11 | John Kozlowski | 5 | son | — | Pennsylvania |
| 12 | Theresa Kozlowski | 3 | daughter | — | Pennsylvania |
| 13 | John Karpinski | 27 | head | Laborer | Pennsylvania |
| 14 | Sophie Karpinski | 25 | sister | Laborer | Pennsylvania |
| 15 | Genevieve Karpinski | 20 | sister | — | Pennsylvania |
| 16 | Francis Karpinski | 17 | brother | New Worker | Pennsylvania |
| 17 | Edward Karpinski | 15 | brother | — | Pennsylvania |
| 18 | Frances Karpinski | 10 | brother | — | Pennsylvania |
| 19 | Dorothy Milka | 8 | cousin | — | Pennsylvania |
| 20 | Elizabeth Ritter | 69 | head | — | Pennsylvania |
| 21 | Kempton Mcnutt | 38 | head | Assistant Editor | Pennsylvania |
| 22 | Annetta Mcnutt | 38 | wife | — | Pennsylvania |
| 23 | Annetta E. Mcnutt | 10 | daughter | — | Pennsylvania |
| 24 | John L. Caruso | 30 | head | Manager | Italy |
| 25 | Ruth Caruso | 26 | wife | — | Pennsylvania |
| 26 | John L. Caruso | 2 | son | — | Pennsylvania |
| 27 | August Teresi | 42 | head | Truck Driver | Italy |
| 28 | Lena B. Teresi | 33 | sister | Manager | Pennsylvania |
| 29 | Frank Teresi | 30 | brother | Truck Driver | Pennsylvania |
| 30 | Rose Teresi | 27 | sister | Laboratory Technician | Pennsylvania |
| 31 | Clarence B. Harbison | 57 | lodger | Painter & Paperhanger | Pennsylvania |
| 32 | Joseph Balkey | 45 | head | Proprietor | Pennsylvania |
| 33 | Mary Balkey | 42 | wife | Sales Clerk | Pennsylvania |
| 34 | Joseph Balkey | 19 | son | Radio Serviceman | Pennsylvania |
| 35 | Elizabeth Balkey | 18 | daughter | — | Pennsylvania |
| 36 | Colin Balkey | 15 | son | — | Pennsylvania |
| 37 | Mildred Balkey | 13 | daughter | — | Pennsylvania |
| 38 | Paul Balkey | 9 | son | — | Pennsylvania |
| 39 | Clyde Balkey | 7 | son | — | Pennsylvania |
| 40 | Audrey Balkey | 5 | daughter | — | Pennsylvania |
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)