JK
John Kozlowski — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Middlesex-County, New Jersey
Our Model Tree links this John Kozlowski across the 1930 and 1940 US Censuses in Middlesex-County, New Jersey (XGBoost, ~Confirmed) — first a son (b.~1916), then head of a 9-person household.
Age 24
b. ~1916
Male
Son
Born: New Jersey
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Middlesex-County, New Jersey |
| Surname | Kozlowski |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 24 |
| Marital Status | Single |
| Birthplace | New Jersey |
| 1935 Residence (City) | Perth Amboy City |
| 1935 Residence (County) | Middlesex |
| Additional Details | |
| Occupation | Laborer |
| Industry | Copper Refining |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 0 |
| Highest Grade | No 6 |
| 1935 Residence | Same place |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
| Occupation | Laborer |
| Township / Ward | Perth Amboy City |
| Est. Birth Year | ~1916 |
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.
9 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Mary Kozlowski | Spouse | — | 48 | ~1892 |
| Alexander Kozlowski | Head | — | 50 | ~1890 |
| John Kozlowski | Son | — | 24 | ~1916 |
| Helen Kozlowski | Daughter | — | 12 | ~1928 |
| Frank Kozlowski | Son | — | 28 | ~1912 |
| Joseph Kozlowski | Son | — | 14 | ~1926 |
| Walter Kozlowski | Son | — | 18 | ~1922 |
| Stanley Kozlowski | Son | — | 27 | ~1913 |
| Bernice Kozlowski | Daughter | — | 21 | ~1919 |
Census Appearances
1930
Middlesex, New …
Son, age 13
Middlesex, New Jersey · implied b. ~1917 — 11 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kozlowsky |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | New Jersey |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Can Read/Write | Yes |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
1940
Middlesex-County, New …
Son, age 24
Middlesex-County, New Jersey · implied b. ~1916 — 9 household members
| Surname | Kozlowski |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 24 |
| Marital Status | Single |
| Birthplace | New Jersey |
| 1935 Residence (City) | Perth Amboy City |
| 1935 Residence (County) | Middlesex |
| Occupation | Laborer |
| Industry | Copper Refining |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 0 |
| Highest Grade | No 6 |
| 1935 Residence | Same place |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
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 John Kozlowski across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Kozlowski
Son · 1940 · age 24 · b. ~1916 · New Jersey
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Sibling
Frank Kozlowski
Sibling · 1940 · age 28
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Kozlowski
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Walter Kozlowski
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Stanley Kozlowski
Sibling · 1940 · age 27
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Bernice Kozlowski
Sibling · 1940 · age 21
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Helen Kozlowski
Sibling · 1940 · age 12
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 — Middlesex-County, New Jersey
Open full size
1940 US Federal Census — Middlesex-County, New Jersey
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-02362-00276)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Anthony J. Urban | 14 | Son | — | New Jersey |
| 42 | Theresa Urban | 7 | Daughter | — | New Jersey |
| 43 | Joseph Kanchie | 31 | Head | Shell-Laborer | New Jersey |
| 44 | Sophie Kanchie | 28 | Wife | — | New Jersey |
| 45 | Claire Kanchie | 5 | Daughter | — | New Jersey |
| 46 | Stephen Barna | 45 | Head | Fireman | Hungary |
| 47 | Pauline Barna | 45 | Wife | — | Hungary |
| 48 | James Barna | 20 | Son | Laborer | New Jersey |
| 49 | Margaret Barna | 16 | Daughter | — | New Jersey |
| 50 | Frank Barna | 13 | Son | — | New Jersey |
| 51 | Mary Segedi | 61 | Lodger | — | Hungary |
| 52 | Stanley Smisko | 27 | Head | Laborer | New Jersey |
| 53 | Anne Smisko | 24 | Wife | — | New Jersey |
| 54 | Alexander Kozlowski | 50 | Head | Laborer | Poland |
| 55 | Mary Kozlowski | 48 | Wife | — | Poland |
| 56 | Frank Kozlowski | 28 | Son | Handy Man | New Jersey |
| 57 | Stanley Kozlowski | 27 | Son | Laborer | New Jersey |
| 58 | John Kozlowski THIS PERSON | 24 | Son | Laborer | New Jersey |
| 59 | Bernice Kozlowski | 21 | Daughter | Handy Girl | New Jersey |
| 60 | Walter Kozlowski | 18 | Son | — | New Jersey |
| 61 | Joseph Kozlowski | 14 | Son | — | New Jersey |
| 62 | Helen Kozlowski | 12 | Daughter | — | New Jersey |
| 63 | Albert Slonikovski | 25 | Head | Laborer | Kentucky |
| 64 | Martha Slonikovski | 25 | Wife | — | New Jersey |
| 65 | John Boyko | 50 | Head | Laborer | Austria |
| 66 | Sophie Boyko | 42 | Wife | Cigar Maker | Austria |
| 67 | Michael Boyko | 20 | Son | Laborer | New Jersey |
| 68 | John Boyko | 16 | Son | — | New Jersey |
| 69 | Joseph Kovalik | 59 | Head | Laborer | Slovakia |
| 70 | Theresa Kovalik | 54 | Wife | — | Slovakia |
| 71 | Charles Kovalik | 27 | Son | Laborer | New Jersey |
| 72 | Joseph Jr. Kovalik | 23 | Son | House Painter | New Jersey |
| 73 | Mary Kovalik | 21 | Daughter | Handy Girl | New Jersey |
| 74 | Mary Skowronski | 45 | Head | — | Poland |
| 75 | Helen Skowronski | 20 | Daughter | Handy Girl | New Jersey |
| 76 | Mary Skowronski | 18 | Daughter | Cleaning Girl | New Jersey |
| 77 | Dorothy Skowronski | 16 | Daughter | New Worker | New Jersey |
| 78 | Stella Skowronski | 13 | Daughter | — | New Jersey |
| 79 | John Kazimierz | 44 | Head | Iron-Pigger | New Jersey |
| 80 | Mary Kazimierz | 36 | Wife | — | New Jersey |
Related Census Records
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)