MD
Mary Duffy — 1940 US Census Record
Model Tree available1940 United States Federal Census · Suffolk-County, Massachusetts
Our Model Tree links this Mary Duffy across the 1920, 1930 and 1940 US Censuses in Suffolk-County, Massachusetts (XGBoost, ~Confirmed), with identified parents John & Joseph — first a daughter (b.~1911), then head of a 3-person household.
Age 29
b. ~1911
Female
Daughter
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Suffolk-County, Massachusetts |
| Surname | Duffy |
| Given Name | Mary E. |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 29 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Boston City |
| 1935 Residence (County) | Suffolk |
| Additional Details | |
| Occupation | Telephone Operator |
| Industry | Publishing House |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 242 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same house |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Telephone Operator |
| Township / Ward | Boston City |
| Est. Birth Year | ~1911 |
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 Mary | Age | Birth yr |
|---|---|---|---|---|
| Mary Duffy | Daughter | — | 29 | ~1911 |
| John Duffy | Head | — | 52 | ~1888 |
| Ellen Duffy | Spouse | — | 49 | ~1891 |
Census Appearances
1920
Suffolk, Massachusetts
Daughter, age 9
Suffolk, Massachusetts · implied b. ~1911 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 9 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1930
Suffolk, Massachusetts
Daughter, age 19
Suffolk, Massachusetts · implied b. ~1911 — 8 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | Mary E. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 19 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Occupation | Clerk-Typist |
| Industry | Office |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Suffolk-County, Massachusetts
Daughter, age 29
Suffolk-County, Massachusetts · implied b. ~1911 — 3 household members
| Surname | Duffy |
| Given Name | Mary E. |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 29 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Boston City |
| 1935 Residence (County) | Suffolk |
| Occupation | Telephone Operator |
| Industry | Publishing House |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 242 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same house |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
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 Duffy across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father John Duffy (~0.92 confidence) and father Joseph Duffy (~0.92 confidence) and mother Catherine Duffy (~0.92 confidence) and father Joseph Duffy (~0.92 confidence) and mother Ellen Duffy (~0.92 confidence). The pedigree spans 1 generation with 5 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
John Duffy
b. ~1888
Source father
● Household
· direct · ~0.92
Father
Joseph Duffy
b. ~1890
Source father
● Household
· direct · ~0.92
Mother
Catherine Duffy
b. ~1890
Source mother
● Household
· direct · ~0.92
Father
Joseph Duffy
b. ~1891
Source father
● Household
· direct · ~0.92
Mother
Ellen Duffy
b. ~1891
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Mary Duffy
Daughter · 1940 · age 29 · b. ~1911 · Massachusetts
★ 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 — 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-t0627-01668-00606)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Ellen Killian | 85 | Head | — | Ireland |
| 2 | Mary Brennan | 59 | daughter | — | New Hampshire |
| 3 | Katherine I. Brennan | 49 | daughter | Seamstress | Massachusetts |
| 4 | Anthony Lenta | 53 | Head | Barber | Italy |
| 5 | Mary A. Lenta | 52 | wife | — | Massachusetts |
| 6 | Frances T. Lenta | 29 | daughter | Rate Clerk | Massachusetts |
| 7 | Fred Marden | 62 | Head | Mechanic | Massachusetts |
| 8 | Mary Marden | 63 | Wife | — | Norway |
| 9 | Frederick T. Marden | 39 | son | Mechanic | Massachusetts |
| 10 | Lawrence J. Cavanaugh | 33 | nephew | Shoe Designer | Massachusetts |
| 11 | Thomas W. Quigley | 30 | Head | Adjuster | Massachusetts |
| 12 | Marie T. Quigley | 27 | wife | — | Massachusetts |
| 13 | Thomas V. Quigley | 2 | son | — | Massachusetts |
| 14 | Mary A. Martin | 55 | Head | — | Massachusetts |
| 15 | Ruth C. Martin | 24 | daughter | Hairdresser | Massachusetts |
| 16 | Francis G. Martin | 23 | son | — | Massachusetts |
| 17 | Elizabeth H. Bluhm | 87 | Head | — | Germany |
| 18 | Elizabeth M. Bluhm | 54 | daughter | Clerk, Typist | Germany |
| 19 | Betty J. Bluhm | 51 | daughter | — | New York |
| 20 | William A. Ross | 32 | Head | Electrician | Massachusetts |
| 21 | Mary E. Ross | 30 | Wife | — | Massachusetts |
| 22 | John W. Ross | 9 | son | — | Massachusetts |
| 23 | Edward T. Ross | 7 | son | — | Massachusetts |
| 24 | Mary E. Ross | 5 | daughter | — | Massachusetts |
| 25 | John J. Rourke | 65 | Head | Baker | Irish Free State |
| 26 | Delia T. Rourke | 63 | wife | — | Irish Free State |
| 27 | John T. Rourke | 30 | son | Machinist | Massachusetts |
| 28 | Joseph M. Rourke | 28 | son | Clerk | Massachusetts |
| 29 | Henry Rourke | 25 | son | Labor | Massachusetts |
| 30 | Thomas Rourke | 21 | son | Welder | Massachusetts |
| 31 | Mary L. Kirby | 82 | Head | — | Massachusetts |
| 32 | Willis M. Fuller | 82 | lodger | — | Connecticut |
| 33 | John C. Nees | 53 | lodger | — | Wisconsin |
| 34 | Alfred Treano | 65 | Head | Silver-Polisher | Italy |
| 35 | Susan Treano | 52 | wife | Bridge Builder | Italy |
| 36 | Mary F. Treano | 31 | daughter | — | Massachusetts |
| 37 | Eleanor A. Treano | 26 | daughter | — | Massachusetts |
| 38 | John F. Duffy | 52 | Head | Waitress | Michigan |
| 39 | Ellen Duffy | 49 | Wife | Sales-Clerk | Northern Ireland |
| 40 | Mary E. Duffy THIS PERSON | 29 | daughter | Telephone Operator | Massachusetts |
Pedigree Summary
Mary
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)