MK
Mary Kowalski — 1940 US Census Record
Linked across censuses1940 United States Federal Census · St.-Joseph-County, Indiana
Our Model Tree links this Mary Kowalski across the 1930 and 1940 US Censuses in St.-Joseph-County, Indiana (XGBoost, ~Confirmed) — first a daughter (b.~1917), then head of a 9-person household.
Age 23
b. ~1917
Female
Daughter
Born: Indiana
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | St.-Joseph-County, Indiana |
| Surname | Kowalski |
| Given Name | Mary |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Indiana |
| 1935 Residence (City) | South Bend |
| 1935 Residence (County) | St Joseph |
| Additional Details | |
| Occupation | Laundry |
| Industry | men's college laundry |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 350 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same house |
| Birth State | Indiana |
| Birth Country | United States |
| Birthplace (normalized) | indiana |
| Occupation | Laundry |
| Township / Ward | South Bend |
| Est. Birth Year | ~1917 |
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 Mary | Age | Birth yr |
|---|---|---|---|---|
| Edmund Kowalski | Son | — | 25 | ~1915 |
| Henrietta Kowalski | Daughter | — | 17 | ~1923 |
| Richard Kowalski | Son | — | 14 | ~1926 |
| Freda Kowalski | Daughter | — | 26 | ~1914 |
| Mary Kowalski | Daughter | — | 23 | ~1917 |
| Katherine Kowalski | Spouse | — | 51 | ~1889 |
| Eugene Kowalski | Son | — | 14 | ~1926 |
| Stanley Kowalski | Head | — | 54 | ~1886 |
| Chester Kowalski | Son | — | 19 | ~1921 |
Census Appearances
1930
St Joseph, …
Daughter, age 13
St Joseph, Indiana · implied b. ~1917 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Indiana |
| Father's Birthplace | Indiana |
| Mother's Birthplace | Poland |
| Can Read/Write | Yes |
| Birth State | Indiana |
| Birth Country | United States |
| Birthplace (normalized) | indiana |
1940
St.-Joseph-County, Indiana
Daughter, age 23
St.-Joseph-County, Indiana · implied b. ~1917 — 9 household members
| Surname | Kowalski |
| Given Name | Mary |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Indiana |
| 1935 Residence (City) | South Bend |
| 1935 Residence (County) | St Joseph |
| Occupation | Laundry |
| Industry | men's college laundry |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 350 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same house |
| 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 Mary Kowalski across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Kowalski
Daughter · 1940 · age 23 · b. ~1917 · Indiana
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Sibling
Chester Kowalski
Sibling · 1940 · age 19
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Freda Kowalski
Sibling · 1940 · age 26
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Henrietta Kowalski
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Eugene Kowalski
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Richard Kowalski
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edmund Kowalski
Sibling · 1940 · age 25
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 — St.-Joseph-County, Indiana
Open full size
1940 US Federal Census — St.-Joseph-County, Indiana
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01133-00617)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Delores Jops | 6 | daughter | — | Indiana |
| 42 | Chester Herman | 12 | Roomer | — | Indiana |
| 43 | Josephine Kubiak | 67 | Sister-in-law | — | Poland |
| 44 | Stanley Kowalski | 54 | Head | Moulder | Poland |
| 45 | Katherine Kowalski | 51 | wife | — | Poland |
| 46 | Freda Kowalski | 26 | daughter | Stenographer | Indiana |
| 47 | Edmund Kowalski | 25 | son | — | Indiana |
| 48 | Mary Kowalski THIS PERSON | 23 | daughter | Laundry | Indiana |
| 49 | Chester Kowalski | 19 | son | Laborer | Indiana |
| 50 | Henrietta Kowalski | 17 | daughter | — | Indiana |
| 51 | Richard Kowalski | 14 | son | — | Indiana |
| 52 | Eugene Kowalski | 14 | son | — | Indiana |
| 53 | Sigmund Podemski | 36 | Head | Truck Driver | Indiana |
| 54 | Bernice Podemski | 31 | wife | — | Indiana |
| 55 | Leon Podemski | 13 | son | — | Indiana |
| 56 | Loretta Podemski | 11 | daughter | — | Indiana |
| 57 | Russell King | 41 | Head | Chemical Worker | Indiana |
| 58 | Donnabella King | 29 | wife | — | Indiana |
| 59 | Norma King | 10 | daughter | — | Indiana |
| 60 | Nona King | 10 | daughter | — | Indiana |
| 61 | Nita King | 8 | daughter | — | Indiana |
| 62 | Noel King | 0 | son | — | Indiana |
| 63 | Mitchell Przybyaz | 36 | Head | Core-Maker | Indiana |
| 64 | Stella Przybyaz | 35 | wife | — | Indiana |
| 65 | Delores Przybyaz | 13 | daughter | — | Indiana |
| 66 | Shirley Ann Przybyaz | 5 | daughter | — | Indiana |
| 67 | Antoni Skowronski | 49 | Head | Trimmer | Indiana |
| 68 | Albina Skowronski | 47 | wife | — | Indiana |
| 69 | Anthony Skowronski | 22 | son | Toy-Maker | Indiana |
| 70 | Betty Jane Skowronski | 13 | daughter | — | Indiana |
| 71 | Lewis Sniadecki | 46 | Head | Road-Worker | Michigan |
| 72 | Bernice Sniadecki | 47 | wife | — | Illinois |
| 73 | Geraldine Sniadecki | 10 | daughter | — | Indiana |
| 74 | Joseph Sniadecki | 9 | son | — | Indiana |
| 75 | John Nodijar | 27 | Son-in-law | Salesman | Indiana |
| 76 | Bernadine Nodijar | 21 | daughter | — | Indiana |
| 77 | John Polwaski | 75 | Head | Watch Man | Poland |
| 78 | Frank Polwaski | 42 | son | Machine-Operator | Indiana |
| 79 | Stanley Polwaski | 40 | son | Machine-Operator | Indiana |
| 80 | Benjamin Polwaski | 18 | Grandson | Roofers-Helper | 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)