MK
Mary Kozlowski — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Montgomery-County, Pennsylvania
Our Model Tree links this Mary Kozlowski across the 1930 and 1940 US Censuses in Montgomery-County, Pennsylvania (XGBoost, ~Confirmed) — first a spouse (b.~1894), then head of a 8-person household.
Age 46
b. ~1894
Female
Spouse
Born: Poland
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Montgomery-County, Pennsylvania |
| Surname | Kozlowski |
| Given Name | Mary A. |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 46 |
| Marital Status | Married |
| Birthplace | Poland |
| 1935 Residence (City) | Plymouth Twp |
| 1935 Residence (County) | Montgomery |
| Naturalization Status | First papers filed |
| Additional Details | |
| Industry | H |
| Class of Worker | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same Place |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
| Township / Ward | Plymouth Twp |
| Est. Birth Year | ~1894 |
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 |
|---|---|---|---|---|
| Anthony Kozlowski | Head | — | 50 | ~1890 |
| Boslow Kozlowski | Son | — | 25 | ~1915 |
| Charles Kozlowski | Son | — | 20 | ~1920 |
| John Kozlowski | Son | — | 16 | ~1924 |
| Joseph Kozlowski | Son | — | 9 | ~1931 |
| Antonio Kozlowski | Son | — | 22 | ~1918 |
| Helen Kozlowski | Daughter | — | 18 | ~1922 |
| Mary Kozlowski | Spouse | — | 46 | ~1894 |
Census Appearances
1930
Philadelphia, Pennsylvania
Other, age 35
Philadelphia, Pennsylvania · implied b. ~1895 — 50 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kozlowska |
| Given Name | Mary |
| Relationship to Head | Inmate |
| Sex | F |
| Color / Race | White |
| Age | 35 |
| Marital Status | Single |
| Birthplace | Poland |
| Naturalization Status | Alien |
| Year of Immigration | 1900 |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Occupation | none |
| Can Read/Write | Yes |
| Mother Tongue | Polish |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
1940
Montgomery-County, Pennsylvania
Spouse, age 46
Montgomery-County, Pennsylvania · implied b. ~1894 — 8 household members
| Surname | Kozlowski |
| Given Name | Mary A. |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 46 |
| Marital Status | Married |
| Birthplace | Poland |
| 1935 Residence (City) | Plymouth Twp |
| 1935 Residence (County) | Montgomery |
| Naturalization Status | First papers filed |
| Industry | H |
| Class of Worker | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same Place |
| 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 46 · b. ~1894 · Pennsylvania
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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 — Montgomery-County, Pennsylvania
Open full size
1940 US Federal Census — Montgomery-County, Pennsylvania
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03583-00182)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Kathryn Shannon | 51 | Sister | — | Penna. |
| 2 | Betty Shannon | 9 | Neice | — | Penna. |
| 3 | Joseph G. Smirt | 43 | Head | Engraver | Ohio |
| 4 | Julia E. Smirt | 32 | Wife | — | Kentucky |
| 5 | Joseph J. Smirt | 11 | Son | — | Minnesota |
| 6 | Mary A. Smirt | 10 | Daughter | — | Minnesota |
| 7 | Barbara J. Smirt | 7 | Daughter | — | Minnesota |
| 8 | Patricia R. Smirt | 2 | Daughter | — | Michigan |
| 9 | Mary H. Smirt | 67 | Mother | — | Kentucky |
| 10 | William M. Thomas | 59 | Head | Laborer | Penna. |
| 11 | Ella M. Thomas | 61 | Wife | — | Penna. |
| 12 | William Jr. Thomas | 28 | Son | Salesman | Penna. |
| 13 | Adam Stryckary | 38 | Head | Laborer | Penna. |
| 14 | Anna Stryckary | 35 | Wife | — | Penna. |
| 15 | Dorothy Stryckary | 13 | Daughter | — | Penna. |
| 16 | Marie Stryckary | 11 | Daughter | — | Penna. |
| 17 | Daniel Leighkep | 59 | Head | Laborer | Penna. |
| 18 | Naomi Leighkep | 60 | Wife | — | Penna. |
| 19 | Anthony Kozlowski | 50 | Head | Laborer | Poland |
| 20 | Mary A. Kozlowski THIS PERSON | 46 | Wife | — | Poland |
| 21 | Boslow Kozlowski | 25 | Son | Laborer | Penna. |
| 22 | Antonio Kozlowski | 22 | Son | Laborer | Penna. |
| 23 | Charles Kozlowski | 20 | Son | Laborer | Penna. |
| 24 | Helen Kozlowski | 18 | Daughter | — | Penna. |
| 25 | John Kozlowski | 16 | Son | — | Penna. |
| 26 | Joseph Kozlowski | 9 | Son | — | Penna. |
| 27 | Walter Campbell | 50 | Head | Laborer | Penna. |
| 28 | Elsie Campbell | 47 | Wife | — | Penna. |
| 29 | John W. Campbell | 24 | Son | Laborer | Penna. |
| 30 | Caroline Campbell | 24 | Daughter-in-law | — | Penna. |
| 31 | James Campbell | 5 | Grand-son | — | Penna. |
| 32 | John Jr. Campbell | 3 | Grand-son | — | Penna. |
| 33 | Harry Campbell | 1 | Grand-son | — | Penna. |
| 34 | Thomas Campbell | 1 | Grand-son | — | Penna. |
| 35 | Jonathan Phiffs | 73 | Father-in-law | — | Penna. |
| 36 | Harland Smith | 29 | Head | Salesman | Penna. |
| 37 | Marion Smith | 31 | Wife | — | Penna. |
| 38 | Harland Jr. Smith | 3 | Son | — | Penna. |
| 39 | G. Marion Smith | 0 | Daughter | — | Penna. |
| 40 | Harry Campbell | 40 | Head | Foreman | Penna. |
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)