JK
John Kowalski — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this John Kowalski across the 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a son (b.~1918), then head of a 9-person household.
Age 22
b. ~1918
Male
Son
Born: Indiana
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Kowalski |
| Given Name | John Jr. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 22 |
| Marital Status | Single |
| Birthplace | Indiana |
| 1935 Residence (City) | Chicago city |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Occupation | laborer |
| Industry | steel mill |
| Class of Worker | PW |
| Hours Worked | 9 |
| Income (1939) | 988 |
| Highest Grade | Hs 2 |
| 1935 Residence | Same place |
| Birth State | Indiana |
| Birth Country | United States |
| Birthplace (normalized) | indiana |
| Occupation | Laborer |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1918 |
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 |
|---|---|---|---|---|
| John Kowalski | Son | — | 22 | ~1918 |
| Edward Kowalski | Son | — | 6 | ~1934 |
| Eugene Kowalski | Son | — | 17 | ~1923 |
| Irene Kowalski | Daughter | — | 14 | ~1926 |
| Ernest Kowalski | Son | — | 12 | ~1928 |
| Stella Kowalski | Spouse | — | 42 | ~1898 |
| John Kowalski | Head | — | 43 | ~1897 |
| Walter Kowalski | Son | — | 19 | ~1921 |
| June Kowalski | Daughter | — | 13 | ~1927 |
Census Appearances
1930
Cook, Illinois
Son, age 11
Cook, Illinois · implied b. ~1919 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | John W. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Indiana |
| Father's Birthplace | Illinois |
| Mother's Birthplace | Indiana |
| Can Read/Write | Yes |
| Birth State | Indiana |
| Birth Country | United States |
| Birthplace (normalized) | indiana |
1940
Cook-County, Illinois
Son, age 22
Cook-County, Illinois · implied b. ~1918 — 9 household members
| Surname | Kowalski |
| Given Name | John Jr. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 22 |
| Marital Status | Single |
| Birthplace | Indiana |
| 1935 Residence (City) | Chicago city |
| 1935 Residence (County) | Cook |
| Occupation | laborer |
| Industry | steel mill |
| Class of Worker | PW |
| Hours Worked | 9 |
| Income (1939) | 988 |
| Highest Grade | Hs 2 |
| 1935 Residence | Same place |
| Birth State | Indiana |
| Birth Country | United States |
| Birthplace (normalized) | indiana |
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 Kowalski across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Kowalski
Son · 1940 · age 22 · b. ~1918 · Illinois
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Sibling
Walter Kowalski
Sibling · 1940 · age 19
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Ernest Kowalski
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Irene Kowalski
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
June Kowalski
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Eugene Kowalski
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Kowalski
Sibling · 1940 · age 6
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 — Cook-County, Illinois
Open full size
1940 US Federal Census — Cook-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00988-00632)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Helen Gintek | 44 | Wife | — | Poland |
| 2 | Steve Gozdzik | 22 | Son | Cabinet Maker | Illinois |
| 3 | Regina Gozdzik | 15 | Daughter | — | Illinois |
| 4 | Frank Budnick | 24 | Head | — | Illinois |
| 5 | Richard Budnick | 4 | Son | — | Illinois |
| 6 | Beverly Budnick | 2 | Daughter | — | Illinois |
| 7 | Adolph Kruszynski | 53 | Head | Laborer | Poland |
| 8 | Sophie Kruszynski | 49 | Wife | Janitress | Poland |
| 9 | John Kruszynski | 26 | Son | Packer | Poland |
| 10 | Stanley Kruszynski | 16 | Son | Candy Packer | Illinois |
| 11 | Teddy Kruszynski | 12 | Son | — | Illinois |
| 12 | Evelyn Kruszynski | 11 | Daughter | — | Illinois |
| 13 | Stanley Jagielski | 24 | Head | Laborer | Pennsylvania |
| 14 | Mary Jagielski | 29 | Wife | — | Illinois |
| 15 | Patricia Jagielski | 6 | Daughter | — | Illinois |
| 16 | Barbara Jagielski | 2 | Daughter | — | Illinois |
| 17 | John Tylutki | 65 | Head | Molder | Poland |
| 18 | Louise Tylutki | 65 | Wife | — | Poland |
| 19 | Florence Tylutki | 38 | Daughter | Candy Packer | Illinois |
| 20 | Barbara Tylutki | 35 | Daughter | — | Illinois |
| 21 | Edward Tylutki | 47 | Head | Laborer | Poland |
| 22 | Alexandra Tylutki | 42 | Wife | — | Poland |
| 23 | Mary Gottkowski | 55 | Head | — | Poland |
| 24 | Helen Gottkowski | 22 | Daughter | Packer | Illinois |
| 25 | Catherine Lentz | 35 | Daughter | Sewer | Illinois |
| 26 | John Lentz | 33 | Son-in-law | Sand Paperer | Illinois |
| 27 | Adolph Galik | 45 | Head | Laborer | Poland |
| 28 | Catherine Galik | 46 | Wife | Gluer | Poland |
| 29 | Ted Galik | 19 | Son | Laborer | Illinois |
| 30 | Frank Galik | 13 | Son | — | Illinois |
| 31 | Bernice Galik | 12 | Daughter | — | Illinois |
| 32 | John Kowalski | 43 | Head | Baker | Poland |
| 33 | Stella Kowalski | 42 | Wife | Clerk | Poland |
| 34 | John Jr. Kowalski THIS PERSON | 22 | Son | Laborer | Indiana |
| 35 | Walter Kowalski | 19 | Son | — | Illinois |
| 36 | Eugene Kowalski | 17 | Son | — | Illinois |
| 37 | Irene Kowalski | 14 | Daughter | — | Illinois |
| 38 | June Kowalski | 13 | Daughter | — | Illinois |
| 39 | Ernest Kowalski | 12 | Son | — | Illinois |
| 40 | Edward Kowalski | 6 | Son | — | Illinois |
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)