MK
Mary Kowalski — 1930 US Census Record
Linked across censuses1930 United States Federal Census · Lucas, Ohio
Our Model Tree links this Mary Kowalski across the 1930 and 1940 US Censuses in Lucas, Ohio (XGBoost, ~Confirmed) — first a son (b.~1928), then head of a 9-person household.
Age 2
b. ~1928
Male
Son
Born: Ohio
Single
1930 Census Record Details
| Census Year | 1930 |
| Location | Lucas, Ohio |
| Surname | Kowalski |
| Given Name | Mary Jr |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 2 |
| Marital Status | Single |
| Birthplace | Ohio |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Additional Details | |
| Birth State | Ohio |
| Birth Country | United States |
| Birthplace (normalized) | ohio |
| Township / Ward | Toledo |
| Est. Birth Year | ~1928 |
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 1930 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Frank Kowalski | Son | — | 10 | ~1920 |
| Wallace Kowalski | Son | — | 22 | ~1908 |
| Mary Kowalski | Son | — | 2 | ~1928 |
| Clara Kowalski | Daughter | — | 17 | ~1913 |
| Max Kowalski | Head | — | 45 | ~1885 |
| Lillian Kowalski | Daughter | — | 6 | ~1924 |
| Hattie Kowalski | Spouse | — | 40 | ~1890 |
| Roman Kowalski | Son | — | 15 | ~1915 |
| Harry Kowalski | Son | — | 13 | ~1917 |
Census Appearances
1930
Lucas, Ohio
Son, age 2
Lucas, Ohio · implied b. ~1928 — 9 household members
| Surname | Kowalski |
| Given Name | Mary Jr |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 2 |
| Marital Status | Single |
| Birthplace | Ohio |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Birth State | Ohio |
| Birth Country | United States |
| Birthplace (normalized) | ohio |
1940
Lucas-County, Ohio
Son, age 13
Lucas-County, Ohio · implied b. ~1927 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kowalski |
| Given Name | Max Jr. |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Ohio |
| 1935 Residence (City) | Toledo City |
| 1935 Residence (County) | Lucas |
| Highest Grade | No 7 |
| 1935 Residence | Same place |
| Birth State | Ohio |
| Birth Country | United States |
| Birthplace (normalized) | ohio |
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
Son · 1930 · age 2 · b. ~1928 · Ohio
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Sibling
Roman Kowalski
Sibling · 1930 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Harry Kowalski
Sibling · 1930 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Lillian Kowalski
Sibling · 1930 · age 6
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Wallace Kowalski
Sibling · 1930 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Clara Kowalski
Sibling · 1930 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Frank Kowalski
Sibling · 1930 · age 10
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
1930 US Federal Census — Lucas, Ohio
Open full size
1930 US Federal Census — Lucas, Ohio
Page Contents
50 people indexed on this census page (ia:1930:ohiocensus00reel1834:0402)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 51 | Lucille Tomaszewski | 24 | Wife | — | Poland |
| 52 | Dorothy Tomaszewski | 6 | Daughter | — | Ohio |
| 53 | Loretta Tomaszewski | 4 | Daughter | — | Ohio |
| 54 | Richard Tomaszewski | 1 | Son | — | Ohio |
| 55 | Michael Kwiatkowski | 74 | Boarder | Laborer | Poland |
| 56 | Josephine Kwiatkowski | 68 | Boarder | — | Poland |
| 57 | Frank Pruenal | 27 | Head | Machinist | Poland |
| 58 | Pauline Pruenal | 25 | Wife | — | Poland |
| 59 | Dolores Pruenal | 2 | Daughter | — | Ohio |
| 60 | Irene Pigoniak | 12 | Sister-in-law | — | Ohio |
| 61 | Chester Pigoniak | 15 | Brother-in-law | — | Ohio |
| 62 | Walter Rylicki | 36 | Head | Laborer | Poland |
| 63 | Celia Rylicki | 39 | Wife | Assembler | Poland |
| 64 | Anthony Turbaczewski | 47 | Head | Laborer | Poland |
| 65 | John Siewierski | 59 | Boarder | Carpenter | Poland |
| 66 | Stanley Lenkowski | 27 | Head | Proprietor | Ohio |
| 67 | Pauline Lenkowski | 27 | Wife | — | Ohio |
| 68 | Raymond Lenkowski | 7 | Son | — | Ohio |
| 69 | Adeline Lenkowski | 2 | Daughter | — | Ohio |
| 70 | Lillian Lenkowski | 1 | Daughter | — | Ohio |
| 71 | Eleanor Lenkowski | 0 | Daughter | — | Ohio |
| 72 | Beatrice Lenkowski | 1 | Daughter | — | Ohio |
| 73 | Leo Bartnik | 19 | Boarder | — | Ohio |
| 74 | Evelyn Linkowski | 3 | Daughter | — | Ohio |
| 75 | Anthony Luczynski | 78 | Boarder | Retired | Poland |
| 76 | Nicholas Petruczyn | 39 | Head | Fitter | Poland |
| 77 | Mary Petruczyn | 37 | Wife | — | Pennsylvania |
| 78 | Mary Petruczyn | 15 | Daughter | — | Pennsylvania |
| 79 | Josephine Petruczyn | 10 | Daughter | — | Ohio |
| 80 | Margaret Petruczyn | 6 | Daughter | — | Ohio |
| 81 | Leo Zgorecki | 36 | Head | Filer | Poland |
| 82 | Mary Zgorecki | 27 | Wife | — | Poland |
| 83 | Geraldine Zgorecki | 3 | Daughter | — | Ohio |
| 84 | John Kuchinski | 46 | Head | Laborer | Poland |
| 85 | Mary Kuchinski | 49 | Wife | — | Poland |
| 86 | Bertha Kuchinski | 21 | Daughter | Machinist | Poland |
| 87 | Frances Kuchinski | 17 | Daughter | Domestic | Ohio |
| 88 | Chester Kuchinski | 15 | Son | — | Ohio |
| 89 | Martha Kuchinski | 13 | Daughter | — | Ohio |
| 90 | Helen Kuchinski | 11 | Daughter | — | Ohio |
| 91 | Max Kowalski | 45 | Head | Baker | Poland |
| 92 | Hattie Kowalski | 40 | Wife | — | Poland |
| 93 | Wallace Kowalski | 22 | Son | Machinist | Ohio |
| 94 | Roman Kowalski | 15 | Son | Machinist | Ohio |
| 95 | Clara Kowalski | 17 | Daughter | Waitress | Ohio |
| 96 | Harry Kowalski | 13 | Son | — | Ohio |
| 97 | Frank Kowalski | 10 | Son | — | Ohio |
| 98 | Lillian Kowalski | 6 | Daughter | — | Ohio |
| 99 | Mary Jr Kowalski THIS PERSON | 2 | Son | — | Ohio |
| 100 | Simon Ziemieracki | 40 | Head | Millwright | Poland |
About This Record & Model Tree
This record was independently indexed by YourRoots from the 1930 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)