JK
John Kozlowski — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Laporte-County, Indiana
Our Model Tree links this John Kozlowski across the 1930 and 1940 US Censuses in Laporte-County, Indiana (XGBoost, ~Confirmed) — first a head (b.~1889), then head of a 7-person household.
Age 51
b. ~1889
Male
Head
Born: Poland
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Laporte-County, Indiana |
| Surname | Kozlowski |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 51 |
| Marital Status | Married |
| Birthplace | Poland |
| 1935 Residence (City) | La Porte |
| 1935 Residence (County) | La Porte |
| Naturalization Status | Naturalized |
| Additional Details | |
| Occupation | Moulder |
| Industry | Cast Iron Foundry |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 750 |
| Highest Grade | No 4 |
| 1935 Residence | Same house |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
| Occupation | Moulder |
| Township / Ward | La Porte |
| Est. Birth Year | ~1889 |
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 John | Age | Birth yr |
|---|---|---|---|---|
| Louie Kozlowski | Son | — | 8 | ~1932 |
| Mary Kozlowski | Daughter | — | 14 | ~1926 |
| John Kozlowski | Head | — | 51 | ~1889 |
| Julia Kozlowski | Spouse | — | 48 | ~1892 |
| Chester Kozlowski | Son | — | 15 | ~1925 |
| Stanley Kozlowski | Son | — | 20 | ~1920 |
| Adeline Kozlowski | Daughter | — | 11 | ~1929 |
Census Appearances
1930
Lake, Indiana
Head, age 41
Lake, Indiana · implied b. ~1889 — 11 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kozlowski |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 41 |
| Marital Status | Married |
| Birthplace | Poland |
| Naturalization Status | Naturalized |
| Year of Immigration | 1907 |
| Age at First Marriage | 22 |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Occupation | none |
| Can Read/Write | Yes |
| Mother Tongue | Polish |
| Home Owned/Rented | O |
| Home Value / Rent | 3500 |
| Radio Set | R |
| Veteran | No |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
1940
Laporte-County, Indiana
Head, age 51
Laporte-County, Indiana · implied b. ~1889 — 7 household members
| Surname | Kozlowski |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 51 |
| Marital Status | Married |
| Birthplace | Poland |
| 1935 Residence (City) | La Porte |
| 1935 Residence (County) | La Porte |
| Naturalization Status | Naturalized |
| Occupation | Moulder |
| Industry | Cast Iron Foundry |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 750 |
| Highest Grade | No 4 |
| 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 John Kozlowski across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
John Kozlowski
Head · 1940 · age 51 · b. ~1889 · Indiana
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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 — Laporte-County, Indiana
Open full size
1940 US Federal Census — Laporte-County, Indiana
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01069-00068)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Edward Major | 41 | Head | Sprayer | Illinois |
| 42 | Donald Major | 15 | Son | — | Indiana |
| 43 | Doris Major | 17 | Daughter | — | Indiana |
| 44 | Ernest Boyer | 35 | Head | Truck Driver | Indiana |
| 45 | Lilly Boyer | 35 | Wife | — | Ohio |
| 46 | Margaret Boyer | 3 | Daughter | — | Indiana |
| 47 | Elder Biddle | 37 | Head | Paint Shop | Indiana |
| 48 | Evelyn Biddle | 20 | Wife | — | Indiana |
| 49 | Evelyn Biddle | 1 | Daughter | — | Indiana |
| 50 | Russell Shreve | 41 | Head | General Hauling | Indiana |
| 51 | Pearl Shreve | 37 | Wife | — | Ohio |
| 52 | Charles Shreve | 18 | Son | Farm Laborer | Ohio |
| 53 | Marie Shreve | 15 | Daughter | — | Ohio |
| 54 | Richard Ryden | 26 | Head | Sander | Indiana |
| 55 | Catherine Ryden | 20 | Wife | — | Indiana |
| 56 | Richard Pat Ryden | 1 | Son | — | Indiana |
| 57 | Victor Ott | 34 | Head | Greenskeeper | Indiana |
| 58 | Virginia Ott | 32 | Wife | — | Illinois |
| 59 | Robert Ott | 17 | Son | — | Indiana |
| 60 | Leroy Ott | 11 | Son | — | Indiana |
| 61 | Richard Ott | 8 | Son | — | Indiana |
| 62 | Rosalie Ott | 6 | Daughter | — | Indiana |
| 63 | Delyane Ott | 3 | Son | — | Indiana |
| 64 | Allen Ott | 1 | Son | — | Indiana |
| 65 | Charles Manske | 67 | Head | — | Germany |
| 66 | Anna Manske | 79 | Wife | — | Germany |
| 67 | Miecislaus Szczepanek | 27 | Head | Machine Hand | Indiana |
| 68 | Helen Szczepanek | 26 | Wife | Cashier | Indiana |
| 69 | Charles Bordovsky | 54 | Head | Sanding | Czechoslovakia |
| 70 | Paul Kowalski | 55 | Head | Assembly | Russia |
| 71 | Zena Kowalski | 53 | Wife | — | Russia |
| 72 | Jelanita Kowalski | 16 | Daughter | — | Indiana |
| 73 | Baye Vera Kowalski | 19 | Daughter | — | Indiana |
| 74 | John Kozlowski THIS PERSON | 51 | Head | Moulder | Poland |
| 75 | Julia Kozlowski | 48 | Wife | — | Poland |
| 76 | Stanley Kozlowski | 20 | Son | Grocery Clk | Indiana |
| 77 | Chester Kozlowski | 15 | Son | — | Indiana |
| 78 | Mary Kozlowski | 14 | Daughter | — | Indiana |
| 79 | Adeline Kozlowski | 11 | Daughter | — | Indiana |
| 80 | Louie Kozlowski | 8 | Son | — | Indiana |
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)