FK
Frank Kowalski — 1940 US Census Record
Model Tree available1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Frank Kowalski across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed), with identified parents Joseph & Michael — first a son (b.~1906), then head of a 4-person household.
Age 34
b. ~1906
Male
Son
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Kowalski |
| Given Name | Frank |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 34 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago city |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Occupation | punch press feeder |
| Industry | electrical appliance factory |
| Class of Worker | PW |
| Hours Worked | 44 |
| Income (1939) | 496 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Occupation | Punch Press Feeder |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1906 |
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.
4 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Frank | Age | Birth yr |
|---|---|---|---|---|
| Frank Kowalski | Son | — | 34 | ~1906 |
| Joseph Kowalski | Head | — | 64 | ~1876 |
| Michael Wazynski | Daughter | — | 22 | ~1918 |
| Chester Wazynski | Other | — | 27 | ~1913 |
Census Appearances
1920
Cook, Illinois
Son, age 12
Cook, Illinois · implied b. ~1908 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | Frank |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Occupation | none |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1930
Cook, Illinois
Son, age 23
Cook, Illinois · implied b. ~1907 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | Frank |
| Relationship to Head | Son |
| Sex | M |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Occupation | Tool Maker |
| Industry | Automobile Shop |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Son, age 34
Cook-County, Illinois · implied b. ~1906 — 4 household members
| Surname | Kowalski |
| Given Name | Frank |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 34 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago city |
| 1935 Residence (County) | Cook |
| Occupation | punch press feeder |
| Industry | electrical appliance factory |
| Class of Worker | PW |
| Hours Worked | 44 |
| Income (1939) | 496 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
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 Frank Kowalski across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Joseph Kowalski (~0.92 confidence) and father Michael Kowalski (~0.92 confidence) and mother Annie Kowalski (~0.92 confidence) and mother Marie Kowalski (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Joseph Kowalski
b. ~1876
Source father
● Household
· direct · ~0.92
Father
Michael Kowalski
b. ~1879
Source father
● Household
· direct · ~0.92
Mother
Annie Kowalski
b. ~1879
Source mother
● Household
· direct · ~0.92
Mother
Marie Kowalski
b. ~1875
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Frank Kowalski
Son · 1940 · age 34 · b. ~1906 · Illinois
★ You are viewing this record
Sibling
Michael Wazynski
Sibling · 1940 · age 22
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-t0627-00988-00630)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Lucie Pielkowski | 65 | Wife | — | Poland |
| 2 | William Pielkowski | 31 | son | Lawyer | Illinois |
| 3 | Frank M. Pielkowski | 30 | son | Upholsterer | Illinois |
| 4 | Vincent Konwinski | 24 | Head | Paper Box Maker | Illinois |
| 5 | Helen Konwinski | 21 | Wife | — | Illinois |
| 6 | Vincent Jr. Konwinski | 0 | son | — | Illinois |
| 7 | Samuel Rlaszej|Blaszej | 50 | Head | Laborer | Poland |
| 8 | Anna Rlaszej|Blaszej | 50 | Wife | — | Poland |
| 9 | Stanley Witkowski|Witkowsky | 51 | Head | Laborer | Poland |
| 10 | Michael Mazur | 56 | partner | Carpenter | Poland |
| 11 | Ignatius Glowacki | 44 | Head | Shoe Cutter | Poland |
| 12 | Michael Kolski|Rolski | 42 | Head | Laborer | Pennsylvania |
| 13 | Mildred Kolski|Rolski | 39 | Wife | — | Illinois |
| 14 | Virginia Kolski|Rolski | 18 | daughter | Finisher | Illinois |
| 15 | Raymond Kolski|Rolski | 16 | son | Mess. Worker | Illinois |
| 16 | Mildred Kolski|Rolski | 5 | daughter | — | Illinois |
| 17 | Bernadette Kolski|Rolski | 1 | daughter | — | Illinois |
| 18 | Joseph Kowalski | 64 | Head | Tailor Maker | Poland |
| 19 | Frank Kowalski THIS PERSON | 34 | son | Punch Press Feeder | Illinois |
| 20 | Michael Wazynski | 22 | daughter | — | Illinois |
| 21 | Chester Wazynski | 27 | son-in-law | Refrigerator Installer | Illinois |
| 22 | Ignatius Kolczynski|Kolczinski | 78 | Head | — | Germany |
| 23 | Elizabeth Cichy | 79 | aunt | — | Germany |
| 24 | Walter Krupa | 32 | Head | Stock Clerk | Illinois |
| 25 | Mary Krupa | 26 | Wife | — | Illinois |
| 26 | Joan Krupa | 0 | daughter | — | Illinois |
| 27 | Joseph Gardof|Gardo | 51 | Head | Presser | Poland |
| 28 | Stella Gardof|Gardo | 50 | Wife | Pocket Setter | Poland |
| 29 | Anna Balicki | 71 | Head | — | Poland |
| 30 | John Ruaner|Ruane | 69 | Head | Laborer | Poland |
| 31 | Veronica Ruaner|Ruane | 61 | Wife | — | Poland |
| 32 | Edward Ruaner|Ruane | 36 | son | Assistant Road Engineer | Illinois |
| 33 | Leo Ruaner|Ruane | 30 | son | Cutter | Illinois |
| 34 | Mitchell Ruaner|Ruane | 25 | son | Shipping Clerk | Illinois |
| 35 | Ray Kucinski | 39 | Head | Finisher | Illinois |
| 36 | May Kucinski | 33 | Wife | — | Illinois |
| 37 | John Gryzowski|Gryzowsky | 60 | Head | Laborer | Poland |
| 38 | Hattie Gryzowski|Gryzowsky | 49 | Wife | — | Poland |
| 39 | Tillie Wlazowski|Wlazowsky | 74 | Head | — | Poland |
| 40 | Joseph Mrawczyk|Krawczyk | 24 | Head | Finisher | Illinois |
Pedigree Summary
Frank + 1 sibling
Gen 1 · 4 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)