MK
Mary Kozlowski — 1930 US Census Record
Linked across censuses1930 United States Federal Census · Fairfield, Connecticut
Our Model Tree links this Mary Kozlowski across the 1930 and 1940 US Censuses in Fairfield, Connecticut (XGBoost, ~Confirmed) — first a spouse (b.~1890), then head of a 24-person household.
Age 40
b. ~1890
Female
Spouse
Born: Poland
Married
1930 Census Record Details
| Census Year | 1930 |
| Location | Fairfield, Connecticut |
| Surname | Kozlowski |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 40 |
| Marital Status | Married |
| Birthplace | Poland |
| Naturalization Status | Naturalized |
| Year of Immigration | 1910 |
| Age at First Marriage | 18 |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Additional Details | |
| Can Read/Write | Yes |
| Mother Tongue | Polish |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
| Township / Ward | Bridgeport City |
| Est. Birth Year | ~1890 |
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.
24 people recorded at the same address in the 1930 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Rose Kozlowski | Daughter | — | ~1930 | |
| Helen Kozlowski | Daughter | — | 18 | ~1912 |
| Henry Kozlowski | Son | — | 2 | ~1928 |
| Mary Kozlowski | Daughter | — | ~1930 | |
| Margaret Kozlowski | Daughter | — | ~1930 | |
| Anna Kozlowski | Daughter | — | ~1930 | |
| Frances Kozlowski | Daughter | — | ~1930 | |
| Stanley Kozlowski | Son | — | 12 | ~1918 |
| Sophie Kozlowski | Daughter | — | ~1930 | |
| Martha Kozlowski | Daughter | — | ~1930 | |
| Josephine Kozlowski | Daughter | — | ~1930 | |
| Joseph Kozlowski | Son | — | 10 | ~1920 |
| Alice Kozlowski | Daughter | — | ~1930 | |
| John Kozlowski | Son | — | 16 | ~1914 |
| Theodore Kozlowski | Son | — | ~1930 | |
| Catherine Kozlowski | Daughter | — | ~1930 | |
| Theresa Kozlowski | Daughter | — | ~1930 | |
| Chester Kozlowski | Son | — | 4 | ~1926 |
| Walter Kozlowski | Son | — | 6 | ~1924 |
| Edward Kozlowski | Son | — | 14 | ~1916 |
| Frank Kozlowski | Son | — | 8 | ~1922 |
| Agnes Kozlowski | Daughter | — | ~1930 | |
| Mary Kozlowski | Spouse | — | 40 | ~1890 |
| Elizabeth Kozlowski | Daughter | — | ~1930 |
Census Appearances
1930
Fairfield, Connecticut
Spouse, age 40
Fairfield, Connecticut · implied b. ~1890 — 24 household members
| Surname | Kozlowski |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 40 |
| Marital Status | Married |
| Birthplace | Poland |
| Naturalization Status | Naturalized |
| Year of Immigration | 1910 |
| Age at First Marriage | 18 |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Can Read/Write | Yes |
| Mother Tongue | Polish |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
1940
Hartford-County, Connecticut
Spouse, age 50
Hartford-County, Connecticut · implied b. ~1890 — 2 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Koslowski |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 50 |
| Marital Status | Married |
| Birthplace | Poland |
| 1935 Residence (City) | New Britain City |
| 1935 Residence (County) | Hartford |
| Naturalization Status | Naturalized |
| Occupation | Housework |
| Industry | Home |
| Class of Worker | 0 |
| Highest Grade | No |
| 1935 Residence | Same place |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
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 Kozlowski across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
Mary Kozlowski
Spouse · 1930 · age 40 · b. ~1890 · Connecticut
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Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1930 US Federal Census — Fairfield, Connecticut
Open full size
1930 US Federal Census — Fairfield, Connecticut
Page Contents
74 people indexed on this census page (ia:1930:15thcensus253unit:0603)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Mary Kozlowski THIS PERSON | 40 | Wife | — | Poland |
| 2 | Helen Kozlowski | 18 | Daughter | — | Connecticut |
| 3 | John Kozlowski | 16 | Son | — | Connecticut |
| 4 | Edward Kozlowski | 14 | Son | — | Connecticut |
| 5 | Stanley Kozlowski | 12 | Son | — | Connecticut |
| 6 | Joseph Kozlowski | 10 | Son | — | Connecticut |
| 7 | Frank Kozlowski | 8 | Son | — | Connecticut |
| 8 | Walter Kozlowski | 6 | Son | — | Connecticut |
| 9 | Chester Kozlowski | 4 | Son | — | Connecticut |
| 10 | Henry Kozlowski | 2 | Son | — | Connecticut |
| 11 | Theodore Kozlowski | 0 | Son | — | Connecticut |
| 12 | Sophie Kozlowski | 0 | Daughter | — | Connecticut |
| 13 | Mary Kozlowski | 0 | Daughter | — | Connecticut |
| 14 | Anna Kozlowski | 0 | Daughter | — | Connecticut |
| 15 | Josephine Kozlowski | 0 | Daughter | — | Connecticut |
| 16 | Frances Kozlowski | 0 | Daughter | — | Connecticut |
| 17 | Martha Kozlowski | 0 | Daughter | — | Connecticut |
| 18 | Rose Kozlowski | 0 | Daughter | — | Connecticut |
| 19 | Agnes Kozlowski | 0 | Daughter | — | Connecticut |
| 20 | Catherine Kozlowski | 0 | Daughter | — | Connecticut |
| 21 | Theresa Kozlowski | 0 | Daughter | — | Connecticut |
| 22 | Elizabeth Kozlowski | 0 | Daughter | — | Connecticut |
| 23 | Margaret Kozlowski | 0 | Daughter | — | Connecticut |
| 24 | Alice Kozlowski | 0 | Daughter | — | Connecticut |
| 51 | Donald Mahoney | 23 | Head | Truck Driver | Connecticut |
| 52 | Catherine Mahoney | 23 | Wife | Operator | Connecticut |
| 53 | Adelaide Anderson | 60 | Head | — | Connecticut |
| 54 | Arthur Anderson | 28 | Son | Bookkeeper | Connecticut |
| 55 | Edward F Casey | 47 | Head | Clerk | Massachusetts |
| 56 | Blanch Casey | 35 | Wife | — | Massachusetts |
| 57 | Richard Casey | 12 | Son | — | Massachusetts |
| 58 | Edward Jr Casey | 11 | Son | — | Massachusetts |
| 59 | William H Meaney | 71 | Head | Stereotyper | Connecticut |
| 60 | Lenora Meaney | 51 | Wife | — | Irish Free State |
| 61 | William Meaney | 12 | Son | — | Connecticut |
| 62 | Agatha Meaney | 11 | Daughter | — | Connecticut |
| 63 | Andrew Donahue | 32 | Head | Truck Driver | Connecticut |
| 64 | Josephine Donahue | 30 | Wife | — | Connecticut |
| 65 | Mildred Donahue | 3 | Daughter | — | Connecticut |
| 66 | James Donahue | 50 | Head | Machinist | Connecticut |
| 67 | Margaret Donahue | 45 | Wife | Assembler | Connecticut |
| 68 | Marion Donahue | 25 | Daughter | Sewer | Connecticut |
| 69 | Catherine Donahue | 22 | Daughter | Liner | Connecticut |
| 70 | Sidney Searle | 39 | Head | Master Mechanic | Connecticut |
| 71 | Lucille Searle | 40 | Wife | — | France |
| 72 | Margaret Searle | 11 | Daughter | — | Connecticut |
| 73 | William Mulock | 40 | Head | Millwright | Hungary |
| 74 | Elizabeth Mulock | 31 | Wife | — | Hungary |
| 75 | Catherine Mulock | 7 | Daughter | — | Connecticut |
| 76 | Clara Mulock | 3 | Daughter | — | Connecticut |
| 77 | Margaret Morgan | 67 | Head | Cook | Irish Free State |
| 78 | John Morgan | 33 | Son | — | Connecticut |
| 79 | James Warner | 59 | Head | Tool Maker | New York |
| 80 | Minnie Warner | 59 | Wife | — | Connecticut |
| 81 | William Dunn | 48 | Head | Circulation | Connecticut |
| 82 | Ellen Dunn | 42 | Wife | — | Connecticut |
| 83 | William Dunn | 13 | Son | — | Connecticut |
| 84 | Sarah Dunn | 4 | Daughter | — | Connecticut |
| 85 | William Murtagh | 30 | Head | Machinist | Scotland |
| 86 | Agnes Murtagh | 30 | Wife | — | Scotland |
| 87 | James C Murtagh | 4 | Son | — | Connecticut |
| 88 | Joseph Matthews | 28 | Head | Asst Foreman | Connecticut |
| 89 | Mildred Matthews | 27 | Wife | — | Massachusetts |
| 90 | Joseph Jr Matthews | 5 | Son | — | Connecticut |
| 91 | Elaine Matthews | 6 | Daughter | — | Connecticut |
| 92 | Edw Novotny | 63 | Head | — | Pennsylvania |
| 93 | Mable Novotny | 39 | Daughter | Clerk | Pennsylvania |
| 94 | Thomas Novotny | 24 | Son | Elevator | New Jersey |
| 95 | Carrie Novotny | 27 | Daughter | Winder | Pennsylvania |
| 96 | Frances Novotny | 22 | Daughter | Clerk | New Jersey |
| 97 | John J Cole | 56 | Head | Toolmaker | Connecticut |
| 98 | Emily A Cole | 53 | Wife | — | France |
| 99 | Allen T Cole | 17 | Son | — | Connecticut |
| 100 | Anton Kozlowski | 43 | Head | — | 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)