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John Kozlowski — 1930 US Census Record
Linked across censuses1930 United States Federal Census · Essex, Massachusetts
Our Model Tree links this John Kozlowski across the 1930 and 1940 US Censuses in Essex, Massachusetts (XGBoost, ~Confirmed) — first a head (b.~1888), then head of a 6-person household.
Age 42
b. ~1888
Male
Head
Born: Poland
Married
1930 Census Record Details
| Census Year | 1930 |
| Location | Essex, Massachusetts |
| Surname | Kozlowski |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 42 |
| Marital Status | Married |
| Birthplace | Poland |
| Naturalization Status | Alien |
| Year of Immigration | 1908 |
| Age at First Marriage | 26 |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Additional Details | |
| Occupation | Baker |
| Industry | Baker Shop |
| Class of Worker | W |
| Can Read/Write | Yes |
| Mother Tongue | Polish |
| Home Owned/Rented | R |
| Home Value / Rent | 14.00 |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
| Occupation | Baker |
| Township / Ward | Haverhill City |
| Est. Birth Year | ~1888 |
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.
6 people recorded at the same address in the 1930 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Billy Kozlowski | Son | — | 10 | ~1920 |
| Gladys Kozlowski | Daughter | — | 12 | ~1918 |
| Helen Kozlowski | Other | — | 38 | ~1892 |
| Lucille Kozlowski | Daughter | — | 9 | ~1921 |
| Stella Kozlowski | Daughter | — | 14 | ~1916 |
| John Kozlowski | Head | — | 42 | ~1888 |
Census Appearances
1930
Essex, Massachusetts
Head, age 42
Essex, Massachusetts · implied b. ~1888 — 6 household members
| Surname | Kozlowski |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 42 |
| Marital Status | Married |
| Birthplace | Poland |
| Naturalization Status | Alien |
| Year of Immigration | 1908 |
| Age at First Marriage | 26 |
| Father's Birthplace | Poland |
| Mother's Birthplace | Poland |
| Occupation | Baker |
| Industry | Baker Shop |
| Class of Worker | W |
| Can Read/Write | Yes |
| Mother Tongue | Polish |
| Home Owned/Rented | R |
| Home Value / Rent | 14.00 |
| Birth Country | Poland |
| Birthplace (normalized) | poland |
1940
Essex-County, Massachusetts
Other, age 53
Essex-County, Massachusetts · implied b. ~1887 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Koslowski |
| Given Name | John |
| Relationship to Head | lodger |
| Sex | M |
| Color / Race | White |
| Age | 53 |
| Marital Status | Widowed |
| Birthplace | Poland |
| 1935 Residence (City) | Salem |
| 1935 Residence (County) | Essex |
| Naturalization Status | Naturalized |
| Hours Worked | 40 |
| Highest Grade | No 4 |
| 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 John Kozlowski across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
John Kozlowski
Head · 1930 · age 42 · b. ~1888 · Massachusetts
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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 — Essex, Massachusetts
Open full size
1930 US Federal Census — Essex, Massachusetts
Page Contents
50 people indexed on this census page (ia:1930:massachusettscensus00reel896:0818)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 51 | Andrew Bambis | 10 | Son | — | Massachusetts |
| 52 | Mary Bambis | 8 | Daughter | — | Massachusetts |
| 53 | Julian Bambis | 6 | Son | — | Massachusetts |
| 54 | John Kozlowski THIS PERSON | 42 | Head | Baker | Poland |
| 55 | Helen Kozlowski | 38 | Wife-H | — | Poland |
| 56 | Stella Kozlowski | 14 | Daughter | — | New Hampshire |
| 57 | Gladys Kozlowski | 12 | Daughter | — | New Hampshire |
| 58 | Billy Kozlowski | 10 | Son | — | New Hampshire |
| 59 | Lucille Kozlowski | 9 | Daughter | — | New Hampshire |
| 60 | Thomas Holodziej | 38 | Head | — | Poland |
| 61 | Amelia Holodziej | 33 | Wife-H | Burnisher | Poland |
| 62 | Ludwick Holodziej | 12 | Son | — | Massachusetts |
| 63 | Anna Holodziej | 10 | Daughter | — | Massachusetts |
| 64 | Gladys Holodziej | 6 | Daughter | — | Massachusetts |
| 65 | Wasil Tomzak | 52 | Head | Janitor | Poland |
| 66 | Rose Tomzak | 44 | Wife-H | — | Poland |
| 67 | Anna Tomzak | 22 | Daughter | — | Maine |
| 68 | Alexander Tomzak | 20 | Son | — | Maine |
| 69 | John Tomzak | 15 | Son | — | Massachusetts |
| 70 | Lena Siltery | 42 | Head-H.R. | — | Russia |
| 71 | Eli Siltery | 24 | Son | Expressman | Massachusetts |
| 72 | Herbert Siltery | 22 | Son | Stockman | Massachusetts |
| 73 | Louis Garlow | 32 | Son-in-law | Skiver | Russia |
| 74 | Minnie Garlow | 26 | Daughter | — | Massachusetts |
| 75 | Shirley Garlow | 3 | Gr. Daughter | — | Massachusetts |
| 76 | Charlotte H. Pool | 63 | Head | Shoe Cutter | Massachusetts |
| 77 | Addie D. Pool | 59 | Wife-H | — | Massachusetts |
| 78 | Ruth A. Pool | 37 | Daughter | Book Keeper | Massachusetts |
| 79 | Victor Peke | 54 | Head-H. | — | Russia |
| 80 | William Peke | 29 | Son | Electrical Work | Massachusetts |
| 81 | Michael Peke | 25 | Son | Salesman | Massachusetts |
| 82 | Charles Peke | 22 | Son | Collector | Massachusetts |
| 83 | Jennie Peke | 18 | Daughter | Book Keeper | Massachusetts |
| 84 | Joseph James | 54 | Head | Laster | Russia |
| 85 | Geraldine James | 38 | Wife-H | Stitching Mach. | Russia |
| 86 | Philip James | 21 | Son | Salad Dressing | Massachusetts |
| 87 | Walter James | 14 | Son | — | Massachusetts |
| 88 | Andrew Bambis | 35 | Head | Laster | Poland |
| 89 | Rose Bambis | 34 | Wife-H | — | Poland |
| 90 | Modrick Bambis | 14 | Son | — | Massachusetts |
| 91 | Frank Bambis | 12 | Son | — | Massachusetts |
| 92 | Annie Bambis | 10 | Daughter | — | Massachusetts |
| 93 | Michael Bambis | 6 | Son | — | Massachusetts |
| 94 | Emil Bambis | 3 | Son | — | Massachusetts |
| 95 | Sigmund Zulhiewski | 38 | Head | Sole Layer | Russia |
| 96 | Anna Zulhiewski | 33 | Wife-H | — | Poland |
| 97 | John Stachulski | 45 | Head | Beater In Paper | Poland |
| 98 | Sophia Stachulski | 36 | Wife-H | — | Poland |
| 99 | Joseph Stachulski | 12 | Son | — | Massachusetts |
| 100 | Stanley Stachulski | 11 | Son | — | Massachusetts |
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)