JD
John Duffy — 1940 US Census Record
Model Tree available1940 United States Federal Census · Hudson-County, New Jersey
Our Model Tree links this John Duffy across the 1920, 1930 and 1940 US Censuses in Hudson-County, New Jersey (XGBoost, ~Confirmed), with identified parents Mary & Luke — first a son (b.~1905), then head of a 3-person household.
Age 35
b. ~1905
Male
Son
Born: New Jersey
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Hudson-County, New Jersey |
| Surname | Duffy |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 35 |
| Marital Status | Single |
| Birthplace | New Jersey |
| 1935 Residence (City) | Hoboken City |
| 1935 Residence (County) | Hudson |
| Additional Details | |
| Occupation | Checker |
| Industry | Steamship |
| Class of Worker | PW |
| Hours Worked | 24 |
| Income (1939) | 665 |
| Highest Grade | No 4 |
| 1935 Residence | Same Place |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
| Occupation | Checker |
| Township / Ward | Hoboken City |
| Est. Birth Year | ~1905 |
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.
3 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Luke Duffy | Head | — | 73 | ~1867 |
| John Duffy | Son | — | 35 | ~1905 |
| Catherine Duffy | Spouse | — | 70 | ~1870 |
Census Appearances
1920
Hudson, New …
Son, age 13
Hudson, New Jersey · implied b. ~1907 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | New Jersey |
| Father's Birthplace | New Jersey |
| Mother's Birthplace | New Jersey |
| Occupation | At School |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
1930
Hudson, New …
Son, age 24
Hudson, New Jersey · implied b. ~1906 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 24 |
| Marital Status | Single |
| Birthplace | New Jersey |
| Father's Birthplace | New Jersey |
| Mother's Birthplace | New Jersey |
| Can Read/Write | Yes |
| Veteran | No |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
1940
Hudson-County, New …
Son, age 35
Hudson-County, New Jersey · implied b. ~1905 — 3 household members
| Surname | Duffy |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 35 |
| Marital Status | Single |
| Birthplace | New Jersey |
| 1935 Residence (City) | Hoboken City |
| 1935 Residence (County) | Hudson |
| Occupation | Checker |
| Industry | Steamship |
| Class of Worker | PW |
| Hours Worked | 24 |
| Income (1939) | 665 |
| Highest Grade | No 4 |
| 1935 Residence | Same Place |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
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 Duffy across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: mother Mary Duffy (~0.92 confidence) and father Luke Duffy (~0.92 confidence) and mother Catherine Duffy (~0.92 confidence) and father John Duffy (~0.92 confidence) and mother Marie Duffy (~0.92 confidence). The pedigree spans 1 generation with 5 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Mother
Mary Duffy
b. ~1865
Source mother
● Household
· direct · ~0.92
Father
Luke Duffy
b. ~1867
Source father
● Household
· direct · ~0.92
Mother
Catherine Duffy
b. ~1870
Source mother
● Household
· direct · ~0.92
Father
John Duffy
b. ~1877
Source father
● Household
· direct · ~0.92
Mother
Marie Duffy
b. ~1877
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Duffy
Son · 1940 · age 35 · b. ~1905 · New Jersey
★ You are viewing this record
Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Hudson-County, New Jersey
Open full size
1940 US Federal Census — Hudson-County, New Jersey
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-02348-00565)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Kathryn Mulcahey | 17 | Daughter | — | New Jersey |
| 42 | Dorothy Mulcahey | 13 | Daughter | — | New Jersey |
| 43 | Luke Duffy | 73 | Head | — | Irish Free State |
| 44 | Catherine Duffy | 70 | Wife | — | Irish Free State |
| 45 | John Duffy THIS PERSON | 35 | Son | Checker | New Jersey |
| 46 | Anna Mohr | 67 | Head | — | New Jersey |
| 47 | Amelia L. Mohr | 65 | Sister | — | New Jersey |
| 48 | Emily Mohr | 59 | Sister | — | New Jersey |
| 49 | Ethel M. Mohr | 33 | Daughter | — | New Jersey |
| 50 | Gustav Bruggemann | 63 | Head | Woodfinisher | Germany |
| 51 | Anna Bruggemann | 47 | Wife | — | New York |
| 52 | William Valan | 54 | Head | Laborer | New York |
| 53 | Martha Valan | 48 | Wife | — | New York |
| 54 | John Becker | 42 | Son | Lather | New York |
| 55 | Arthur Becker | 35 | Head | Packer | New Jersey |
| 56 | Mary Becker | 30 | Wife | — | New Jersey |
| 57 | Dorothy Becker | 10 | Daughter | — | New Jersey |
| 58 | Stephen Olsen | 31 | Head | Laborer | New Jersey |
| 59 | James Olsen | 23 | Brother | Laborer | New Jersey |
| 60 | Angelo Speciale | 38 | Head | Presser | Italy |
| 61 | Marion Speciale | 25 | Wife | — | New York |
| 62 | Walter Grabowski | 33 | Head | Kitchenman | Pennsylvania |
| 63 | Konstanc Grabowski | 20 | Wife | — | Pennsylvania |
| 64 | Joan Becker | 32 | Head | Salesgirl | New Jersey |
| 65 | Vilma Johnson | 28 | Roomer | Salesgirl | New Jersey |
| 66 | Margaret Muller | 46 | Head | Household Aide | New Jersey |
| 67 | Robert Muller | 14 | Son | — | New Jersey |
| 68 | Frieda Morenz | 59 | Head | Janitor | Germany |
| 69 | Elizabeth Morenz | 20 | Daughter | Stenographer | Germany |
| 70 | Harry Gitter | 33 | Head | Salesman | Poland |
| 71 | Clara Gitter | 27 | Wife | — | Poland |
| 72 | Barbara Gitter | 3 | Daughter | — | New York |
| 73 | Irving Goldberger | 40 | Head | Dentist | New York |
| 74 | Diana Goldberger | 34 | Wife | — | Russia |
| 75 | Henry Goldberger | 7 | Son | — | New York |
| 76 | Cynthia Goldberger | 2 | Daughter | — | New York |
| 77 | Paul Biller | 32 | Head | Butcher | Germany |
| 78 | Elizabeth Biller | 29 | Wife | — | Germany |
| 79 | Barbara Biller | 0 | Daughter | — | New Jersey |
| 80 | Carroll Doran | 47 | Head | Longshoreman | Pennsylvania |
Pedigree Summary
John
Gen 1 · 5 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)