JK
John Kowalski — 1940 US Census Record
Model Tree available1940 United States Federal Census · Milwaukee-County, Wisconsin
Our Model Tree links this John Kowalski across the 1920, 1930 and 1940 US Censuses in Milwaukee-County, Wisconsin (XGBoost, ~Confirmed), with identified parents John & Mary — first a son (b.~1907), then head of a 8-person household.
Age 33
b. ~1907
Male
Son
Born: Wisconsin
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Milwaukee-County, Wisconsin |
| Surname | Kowalski |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 33 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| 1935 Residence (City) | Milwaukee |
| 1935 Residence (County) | Milwaukee |
| Additional Details | |
| Occupation | Machinist Helper |
| Industry | Railroad Shop |
| Class of Worker | PW |
| Hours Worked | 12 |
| Income (1939) | 1100 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
| Occupation | Machinist Helper |
| Township / Ward | Milwaukee |
| Est. Birth Year | ~1907 |
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 John | Age | Birth yr |
|---|---|---|---|---|
| Anton Kowalski | Son | — | 35 | ~1905 |
| John Kowalski | Son | — | 33 | ~1907 |
| Josephine Kowalski | Head | — | 61 | ~1879 |
| Edmund Kowalski | Son | — | 27 | ~1913 |
| Bernard Sournaski | Other | — | 33 | ~1907 |
| Mary Sournaski | Daughter | — | 32 | ~1908 |
| Leonard Kowalski | Son | — | 24 | ~1916 |
| Ronald Sournaski | Other | — | 3 | ~1937 |
Census Appearances
1920
Milwaukee, Wisconsin
Son, age 10
Milwaukee, Wisconsin · implied b. ~1910 — 16 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 10 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | Polish |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
1930
Milwaukee, Wisconsin
Other, age 20
Milwaukee, Wisconsin · implied b. ~1910 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | John |
| Relationship to Head | Boarder |
| Sex | M |
| Color / Race | White |
| Age | 20 |
| Marital Status | Married |
| Birthplace | Wisconsin |
| Age at First Marriage | 20 |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Occupation | Machinist |
| Industry | Glue Factory |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
1940
Milwaukee-County, Wisconsin
Son, age 33
Milwaukee-County, Wisconsin · implied b. ~1907 — 8 household members
| Surname | Kowalski |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 33 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| 1935 Residence (City) | Milwaukee |
| 1935 Residence (County) | Milwaukee |
| Occupation | Machinist Helper |
| Industry | Railroad Shop |
| Class of Worker | PW |
| Hours Worked | 12 |
| Income (1939) | 1100 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
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 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father John Kowalski (~0.92 confidence) and mother Mary Kowalski (~0.92 confidence) and mother Josephine Kowalski (~0.92 confidence). The pedigree spans 1 generation with 3 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
John Kowalski
b. ~1870
Source father
● Household
· direct · ~0.92
Mother
Mary Kowalski
b. ~1872
Source mother
● Household
· direct · ~0.92
Mother
Josephine Kowalski
b. ~1879
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Kowalski
Son · 1940 · age 33 · b. ~1907 · Wisconsin
★ You are viewing this record
Sibling
Leonard Kowalski
Sibling · 1940 · age 24
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Mary Sournaski
Sibling · 1940 · age 32
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edmund Kowalski
Sibling · 1940 · age 27
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Anton Kowalski
Sibling · 1940 · age 35
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 — Milwaukee-County, Wisconsin
Open full size
1940 US Federal Census — Milwaukee-County, Wisconsin
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-04554-00510)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Eugene Murawski | 13 | Son | — | Wisconsin |
| 2 | Raymond Murawski | 9 | Son | — | Wisconsin |
| 3 | Michael Jr. Murawski | 4 | Son | — | Wisconsin |
| 4 | Josephine Kowalski | 61 | Head | — | Poland |
| 5 | Anton Kowalski | 35 | Son | Shoe Finisher | Wisconsin |
| 6 | John Kowalski THIS PERSON | 33 | Son | Machinist Helper | Wisconsin |
| 7 | Edmund Kowalski | 27 | Son | Baker | Wisconsin |
| 8 | Leonard Kowalski | 24 | Son | New Worker | Wisconsin |
| 9 | Bernard Sournaski | 33 | Son-in-law | Shoe Maker | Wisconsin |
| 10 | Mary Sournaski | 32 | Daughter | — | Wisconsin |
| 11 | Ronald Sournaski | 3 | Grandson | — | Wisconsin |
| 12 | Charles Westhouse | 36 | Head | Steel Inspector | Missouri |
| 13 | Helen Westhouse | 33 | Wife | — | Wisconsin |
| 14 | Donald Westhouse | 8 | Son | — | Wisconsin |
| 15 | Robert Westhouse | 5 | Son | — | Wisconsin |
| 16 | Rose Kujawa | 65 | Head | — | Poland |
| 17 | Bernard Kujawa | 28 | Son | Crancman | Wisconsin |
| 18 | Walter Tafanowski | 47 | Head | Salesman | Wisconsin |
| 19 | Sophie Tafanowski | 45 | Wife | — | Wisconsin |
| 20 | Regina Tafanowski | 20 | Daughter | Saleslady | Wisconsin |
| 21 | Alois Tafanowski | 13 | Son | — | Wisconsin |
| 22 | Ralph Tafanowski | 10 | Son | — | Wisconsin |
| 23 | Stanley Wroblewski | 64 | Head | Sand Mixer | Wisconsin |
| 24 | Anna Wroblewski | 56 | Wife | — | Poland |
| 25 | Joseph Bialozynski | 34 | Son-in-law | Packer Of Preserved Foods | Wisconsin |
| 26 | Casimira Bialozynski | 28 | Daughter | Seamstress | Wisconsin |
| 27 | Richard Bialozynski | 8 | Grandson | — | Wisconsin |
| 28 | Ronald Bialozynski | 3 | Grandson | — | Wisconsin |
| 29 | Ignatz Milonczyk | 62 | Head | Moulder | Poland |
| 30 | Julia Milonczyk | 57 | Wife | — | Poland |
| 31 | Stanley Milonczyk | 30 | Son | Electrical Engineer | Wisconsin |
| 32 | Helen Milonczyk | 27 | Daughter | Seamstress | Wisconsin |
| 33 | Leo Milonczyk | 25 | Son | Sorting Bags | Wisconsin |
| 34 | Alice Milonczyk | 16 | Daughter | — | Wisconsin |
| 35 | Frank Dunajski | 50 | Head | Machinist | Poland |
| 36 | Helene Dunajski | 38 | Wife | — | Poland |
| 37 | Frank Jr. Dunajski | 23 | Son | Machinist | Wisconsin |
| 38 | Sylvia Dunajski | 21 | Daughter | Topper | Wisconsin |
| 39 | Lucille Dunajski | 12 | Daughter | — | Wisconsin |
| 40 | Joseph J. Platko | 47 | Head | Plumber | Wisconsin |
Pedigree Summary
John + 4 siblings
Gen 1 · 3 parents
~0.92
Max depth 4 (1900–1950 window)
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)