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John Duffy — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Suffolk-County, Massachusetts
Our Model Tree links this John Duffy across the 1920, 1930 and 1940 US Censuses in Suffolk-County, Massachusetts (XGBoost, ~Confirmed) — first a head (b.~1875), then head of a 3-person household.
Age 65
b. ~1875
Male
Head
Born: Ireland
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Suffolk-County, Massachusetts |
| Surname | Duffy |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 65 |
| Marital Status | Married |
| Birthplace | Ireland |
| 1935 Residence (City) | Boston |
| 1935 Residence (County) | Suffolk |
| Naturalization Status | Naturalized |
| Additional Details | |
| Occupation | Watchman |
| Industry | Contractor |
| Class of Worker | PW |
| Hours Worked | 32 |
| Income (1939) | 800 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth Country | Ireland |
| Birthplace (normalized) | ireland |
| Occupation | Watchman |
| Township / Ward | Boston |
| Est. Birth Year | ~1875 |
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 |
|---|---|---|---|---|
| Marie Duffy | Daughter | — | 25 | ~1915 |
| John Duffy | Head | — | 65 | ~1875 |
| Marie Duffy | Spouse | — | 62 | ~1878 |
Census Appearances
1920
Suffolk, Massachusetts
Head, age 48
Suffolk, Massachusetts · implied b. ~1872 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | John J |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 48 |
| Marital Status | Married |
| Birthplace | Ireland |
| Year of Immigration | 1888 |
| Naturalization Status | Naturalized |
| Father's Birthplace | Ireland |
| Mother's Birthplace | Ireland |
| Occupation | Waiter |
| Industry | Club |
| Class of Worker | W |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | English |
| Home Owned/Rented | R |
| Birth Country | Ireland |
| Year of Naturalization | 1895 |
| Birthplace (normalized) | ireland |
1930
Suffolk, Massachusetts
Head, age 56
Suffolk, Massachusetts · implied b. ~1874 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | John J. |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 56 |
| Marital Status | Married |
| Birthplace | Ireland |
| Year of Immigration | 1886 |
| Age at First Marriage | 20 |
| Father's Birthplace | Ireland |
| Mother's Birthplace | Ireland |
| Occupation | Waiter |
| Industry | Hotel |
| Class of Worker | W |
| Can Read/Write | Yes |
| Mother Tongue | English |
| Home Owned/Rented | R |
| Home Value / Rent | 25. |
| Radio Set | no |
| Birth Country | Ireland |
| Birthplace (normalized) | ireland |
1940
Suffolk-County, Massachusetts
Head, age 65
Suffolk-County, Massachusetts · implied b. ~1875 — 3 household members
| Surname | Duffy |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 65 |
| Marital Status | Married |
| Birthplace | Ireland |
| 1935 Residence (City) | Boston |
| 1935 Residence (County) | Suffolk |
| Naturalization Status | Naturalized |
| Occupation | Watchman |
| Industry | Contractor |
| Class of Worker | PW |
| Hours Worked | 32 |
| Income (1939) | 800 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth Country | Ireland |
| Birthplace (normalized) | ireland |
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.
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This person
Anchor record
John Duffy
Head · 1940 · age 65 · b. ~1875 · Massachusetts
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Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Suffolk-County, Massachusetts
Open full size
1940 US Federal Census — Suffolk-County, Massachusetts
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01667-00680)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Loretta Paige | 1 | Daughter | — | Massachusetts |
| 2 | Louis Youk | 43 | Head | Machine Operator | Albania |
| 3 | Jennie Youk | 37 | Wife | — | Albania |
| 4 | James Youk | 17 | Son | — | Massachusetts |
| 5 | Dorothy Youk | 15 | Daughter | — | Massachusetts |
| 6 | Mary Youk | 14 | Daughter | — | Massachusetts |
| 7 | Thomas Youk | 10 | Son | — | Massachusetts |
| 8 | John Duffy THIS PERSON | 65 | Head | Watchman | Ireland |
| 9 | Marie Duffy | 62 | Wife | — | Ireland |
| 10 | Marie Duffy | 25 | Daughter | Spring Maker | Massachusetts |
| 11 | James Murphy | 47 | Head | Steam Fitter | Massachusetts |
| 12 | Marie Murphy | 22 | Daughter | Assembler | Massachusetts |
| 13 | Annie Whiteny | 50 | Head | Cook | Massachusetts |
| 14 | Albert J. Hanna | 45 | Head | Machinist | Massachusetts |
| 15 | Julia Hanna | 45 | Wife | — | Massachusetts |
| 16 | Ralph Hanna | 24 | Son | Bell Hop | Massachusetts |
| 17 | Helen Hanna | 20 | Daughter | — | Massachusetts |
| 18 | William Hanna | 12 | Son | — | Massachusetts |
| 19 | Edith Hanna | 6 | Daughter | — | Massachusetts |
| 20 | John Hanna | 5 | Son | — | Massachusetts |
| 21 | Kathryn Formley | 63 | Head | — | New York |
| 22 | James H. Formley | 35 | Son | Painter | Massachusetts |
| 23 | Frank H. Formley | 30 | Son | Manager | Massachusetts |
| 24 | Thomas M. Formley | 25 | Son | Rigger | Massachusetts |
| 25 | William L. Mayo | 39 | Head | Iron Worker | Massachusetts |
| 26 | Evelyn E. Mayo | 34 | Wife | — | Massachusetts |
| 27 | Elizabeth Mayo | 5 | Daughter | — | Massachusetts |
| 28 | Dorothy Mayo | 3 | Daughter | — | Massachusetts |
| 29 | Robert J. Mayo | 2 | Son | — | Massachusetts |
| 30 | Albert H. Mayo | 1 | Son | — | Massachusetts |
| 31 | Edward Alvarez | 49 | Head | Chauffeur | Massachusetts |
| 32 | Rebecca Alvarez | 39 | Wife | — | Massachusetts |
| 33 | Edward Alvarez | 23 | Son | Handyman | Massachusetts |
| 34 | Joseph Alvarez | 21 | Son | Baker | Massachusetts |
| 35 | Mary Alvarez | 18 | Daughter | Packer | Massachusetts |
| 36 | Dorothy Alvarez | 14 | Daughter | — | Massachusetts |
| 37 | Bessie Arnold | 45 | Head | — | Massachusetts |
| 38 | Lewis Arnold | 21 | Son | Bracer | Massachusetts |
| 39 | Catherine Arnold | 18 | Daughter | — | Massachusetts |
| 40 | Virginia Arnold | 15 | Daughter | — | Massachusetts |
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)