JK
John Kowalski — 1940 US Census Record
Model Tree available1940 United States Federal Census · Allegheny-County, Pennsylvania
Our Model Tree links this John Kowalski across the 1920, 1930 and 1940 US Censuses in Allegheny-County, Pennsylvania (XGBoost, ~Confirmed), with identified parents Walter & Phillip — first a head (b.~1913), then head of a 3-person household.
Age 27
b. ~1913
Male
Head
Born: Pennsylvania
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Allegheny-County, Pennsylvania |
| Surname | Kowalski |
| Given Name | John S |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Married |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | NATRONA |
| 1935 Residence (County) | ALLEGHENY |
| Additional Details | |
| Occupation | Crane Man |
| Industry | Steel Mill |
| Class of Worker | PW |
| Hours Worked | 24 |
| Income (1939) | 415 |
| Highest Grade | No 6 |
| 1935 Residence | Same place |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
| Occupation | Crane Man |
| Township / Ward | Natrona |
| Est. Birth Year | ~1913 |
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.
3 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Richard Kowalski | Son | — | 1 | ~1939 |
| John Kowalski | Head | — | 27 | ~1913 |
| Monica Kowalski | Spouse | — | 25 | ~1915 |
Census Appearances
1920
Allegheny, Pennsylvania
Son, age 7
Allegheny, Pennsylvania · implied b. ~1913 — 8 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 7 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Can Read | Yes |
| Can Write | No |
| Speaks English | Yes |
| Mother Tongue | Polish |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1930
Allegheny, Pennsylvania
Son, age 17
Allegheny, Pennsylvania · implied b. ~1913 — 8 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 17 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Age at First Marriage | No |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Can Read/Write | Yes |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1940
Allegheny-County, Pennsylvania
Head, age 27
Allegheny-County, Pennsylvania · implied b. ~1913 — 3 household members
| Surname | Kowalski |
| Given Name | John S |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Married |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | NATRONA |
| 1935 Residence (County) | ALLEGHENY |
| Occupation | Crane Man |
| Industry | Steel Mill |
| Class of Worker | PW |
| Hours Worked | 24 |
| Income (1939) | 415 |
| Highest Grade | No 6 |
| 1935 Residence | Same place |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
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 Walter Kowalski (~0.92 confidence) and father Phillip Kowalski (~0.92 confidence) and mother Veronica Kowalski (~0.92 confidence). The pedigree spans 1 generation with 3 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Walter Kowalski
b. ~1883
Source father
● Household
· direct · ~0.92
Father
Phillip Kowalski
b. ~1889
Source father
● Household
· direct · ~0.92
Mother
Veronica Kowalski
b. ~1889
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Kowalski
Head · 1940 · age 27 · b. ~1913 · Pennsylvania
★ You are viewing this record
Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Allegheny-County, Pennsylvania
Open full size
1940 US Federal Census — Allegheny-County, Pennsylvania
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03405-00339)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Magdalena Dlubak | 60 | Wife | No No No No H | Poland |
| 42 | John S Kowalski THIS PERSON | 27 | Head | Crane Man | Pennsylvania |
| 43 | Monica Kowalski | 25 | Wife | Glass Cutter | Pennsylvania |
| 44 | Richard J. Kowalski | 1 | Son | — | Pennsylvania |
| 45 | Stanley Josefowski | 53 | Head | Crane Loader | Poland |
| 46 | Anna Josefowski | 52 | Wife | No No No No H | Poland |
| 47 | Edward Josefowski | 16 | Son | No No No No S | Pennsylvania |
| 48 | Walter Josefowski | 12 | Son | — | Pennsylvania |
| 49 | William Romanowski | 27 | Head | Cold Roll Catcher | Pennsylvania |
| 50 | Sophie Romanowski | 22 | Wife | No No No No H | Pennsylvania |
| 51 | Steve Evans | 34 | Head | Die Setter | Pennsylvania |
| 52 | Stella Evans | 30 | Wife | No No No No H | Pennsylvania |
| 53 | Carl Evans | 6 | Son | — | Pennsylvania |
| 54 | Roman Majewski | 44 | Head | Cold Roll Worker | Poland |
| 55 | Louise Majewski | 38 | Wife | No No No No H | Pennsylvania |
| 56 | Walter Majewski | 14 | Son | No No No No S | Pennsylvania |
| 57 | Frances Majewski | 10 | Daughter | — | Pennsylvania |
| 58 | Raymond Szymkowiak | 22 | Brother-in-law | Laborer | Pennsylvania |
| 59 | Anthony Wladika | 56 | Head | Blacksmith | Poland |
| 60 | Valeria Wladika | 54 | Wife | No No No No H | Poland |
| 61 | Joseph Wladika | 30 | Son | General Laborer | Pennsylvania |
| 62 | Stan (Ab) Wladika | 25 | Son | Laborer | Pennsylvania |
| 63 | Henry Wladika | 23 | Son | Rod Mill Worker | Pennsylvania |
| 64 | Matthew Wladika | 16 | Son | No No No No S | Pennsylvania |
| 65 | Frank Malik | 41 | Head | Grinder | Czecho-Slovakia |
| 66 | Frances Malik | 46 | Wife | No No No No H | Czecho-Slovakia |
| 67 | Frank Jr Malik | 10 | Son | — | Pennsylvania |
| 68 | Antonia Mrozinski | 74 | Head | No No No No H | Poland |
| 69 | Vincent Mrozinski | 51 | Son | Steel Worker | Illinois |
| 70 | Kazmer Mrozinski | 46 | Son | — | Pennsylvania |
| 71 | Francis Pastor | 33 | Head | Pair Heater | Pennsylvania |
| 72 | Helen Pastor | 38 | Wife | No No No No H | Pennsylvania |
| 73 | Frank Jr Pastor | 12 | Son | — | Pennsylvania |
| 74 | Antoinette M Pastor | 8 | Daughter | — | Pennsylvania |
| 75 | Casimer Kurzawa | 43 | Brother-in-law | Catcher | Pennsylvania |
| 76 | Apolonia Kurzawa | 86 | Mother-in-law | No No No No U | Poland |
| 77 | Vincent Znosko | 55 | Head | Scrapman | Poland |
| 78 | Alice Znosko | 48 | Wife | No No No No H | Poland |
| 79 | Bessie Znosko | 24 | Daughter | Glass Cleaner | Pennsylvania |
| 80 | Sophie Znosko | 23 | Daughter | New Worker | Pennsylvania |
Pedigree Summary
John
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)