WD
William Duffy — 1940 US Census Record
Model Tree available1940 United States Federal Census · Worcester-County, Massachusetts
Our Model Tree links this William Duffy across the 1920, 1930 and 1940 US Censuses in Worcester-County, Massachusetts (XGBoost, ~Confirmed), with identified parents John & John — first a son (b.~1920), then head of a 13-person household.
Age 20
b. ~1920
Male
Son
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Worcester-County, Massachusetts |
| Surname | Duffy |
| Given Name | William |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 20 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Worcester city |
| 1935 Residence (County) | Worcester |
| Additional Details | |
| Occupation | Room Worker |
| Industry | Tire Fabric Co |
| Class of Worker | PW |
| Hours Worked | 5 |
| Income (1939) | 293 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Room Worker |
| Township / Ward | Worcester City |
| Est. Birth Year | ~1920 |
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.
13 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to William | Age | Birth yr |
|---|---|---|---|---|
| Grace Duffy | Daughter | — | 10 | ~1930 |
| Paul Duffy | Son | — | 15 | ~1925 |
| Eleanor Duffy | Daughter | — | 12 | ~1928 |
| John Duffy | Head | — | 45 | ~1895 |
| Richard Duffy | Son | — | 5 | ~1935 |
| William Duffy | Son | — | 20 | ~1920 |
| Gerald Duffy | Son | — | 2 | ~1938 |
| Grace Duffy | Spouse | — | 42 | ~1898 |
| Marjorie Duffy | Daughter | — | 6 | ~1934 |
| Robert Duffy | Son | — | 13 | ~1927 |
| Raymond Duffy | Son | — | 16 | ~1924 |
| Peter Duffy | Son | — | 3 | ~1937 |
| Kathleen Duffy | Daughter | — | 9 | ~1931 |
Census Appearances
1920
Worcester, Massachusetts
Son, age
Worcester, Massachusetts · implied b. ~1920 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | William |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 0 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1930
Worcester, Massachusetts
Son, age 10
Worcester, Massachusetts · implied b. ~1920 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | William |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 10 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Worcester-County, Massachusetts
Son, age 20
Worcester-County, Massachusetts · implied b. ~1920 — 13 household members
| Surname | Duffy |
| Given Name | William |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 20 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Worcester city |
| 1935 Residence (County) | Worcester |
| Occupation | Room Worker |
| Industry | Tire Fabric Co |
| Class of Worker | PW |
| Hours Worked | 5 |
| Income (1939) | 293 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| 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 William 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 John Duffy (~0.92 confidence) and father John Duffy (~0.92 confidence) and mother Grace Duffy (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
John Duffy
b. ~1895
Source father
● Household
· direct · ~0.92
Father
John Duffy
b. ~1895
Source father
● Household
· direct · ~0.92
Father
John Duffy
b. ~1895
Source father
● Household
· direct · ~0.92
Mother
Grace Duffy
b. ~1898
Source mother
● Household
· direct · ~0.92
This person
Anchor record
William Duffy
Son · 1940 · age 20 · b. ~1920 · Massachusetts
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Sibling
Paul Duffy
Sibling · 1940 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Peter Duffy
Sibling · 1940 · age 3
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Richard Duffy
Sibling · 1940 · age 5
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Robert Duffy
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Gerald Duffy
Sibling · 1940 · age 2
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Eleanor Duffy
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Kathleen Duffy
Sibling · 1940 · age 9
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Grace Duffy
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Marjorie Duffy
Sibling · 1940 · age 6
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Raymond Duffy
Sibling · 1940 · age 16
Source co-child of head (derived)
● Co-child · derived · ~0.88
Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Worcester-County, Massachusetts
Open full size
1940 US Federal Census — Worcester-County, Massachusetts
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01715-00359)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Joseph L. Jr. Lian | 6 | son | — | Massachusetts |
| 42 | William J. Guilfoyle | 49 | Head | Clerk | Massachusetts |
| 43 | Helen J. Guilfoyle | 49 | wife | — | New Jersey |
| 44 | Thomas S. Guilfoyle | 19 | son | Salesman | Massachusetts |
| 45 | Richard F. Guilfoyle | 17 | son | — | Massachusetts |
| 46 | Marie T. Guilfoyle | 14 | daughter | — | Massachusetts |
| 47 | Barbara A. Guilfoyle | 12 | daughter | — | Massachusetts |
| 48 | Catherine Guilfoyle | 73 | Head | — | Massachusetts |
| 49 | Mary Tombulian | 57 | sister | Housekeeper | Massachusetts |
| 50 | John Duffy | 45 | Head | Laborer | Massachusetts |
| 51 | Grace Duffy | 42 | wife | — | Massachusetts |
| 52 | William Duffy THIS PERSON | 20 | son | Room Worker | Massachusetts |
| 53 | Raymond Duffy | 16 | son | Odd Jobs | Massachusetts |
| 54 | Paul Duffy | 15 | son | — | Massachusetts |
| 55 | Robert Duffy | 13 | son | — | Massachusetts |
| 56 | Eleanor Duffy | 12 | daughter | — | Massachusetts |
| 57 | Grace Duffy | 10 | daughter | — | Massachusetts |
| 58 | Kathleen Duffy | 9 | daughter | — | Massachusetts |
| 59 | Marjorie Duffy | 6 | daughter | — | Massachusetts |
| 60 | Richard Duffy | 5 | son | — | Massachusetts |
| 61 | Peter Duffy | 3 | son | — | Massachusetts |
| 62 | Gerald Duffy | 2 | son | — | Massachusetts |
| 63 | Peter P. Kowalchek | 32 | Head | Machinist | Pennsylvania |
| 64 | Rose Kowalchek | 33 | wife | — | Massachusetts |
| 65 | Joan Kowalchek | 4 | daughter | — | Massachusetts |
| 66 | Peter Jr. Kowalchek | 2 | son | — | Massachusetts |
| 67 | Herbert H. Ashkin | 38 | Head | Shoe Luster | Massachusetts |
| 68 | Alice Mary Ashkin | 32 | wife | — | Rhode Island |
| 69 | Phyllis C. Ashkin | 1 | daughter | — | Massachusetts |
| 70 | Clifford J. Levia | 32 | Head | Truck-Driver | New Hampshire |
| 71 | Helen Levia | 28 | wife | — | Massachusetts |
| 72 | Jeanette Levia | 10 | daughter | — | Massachusetts |
| 73 | Clifford Jr. Levia | 8 | son | — | Massachusetts |
| 74 | Helen Levia | 7 | daughter | — | Massachusetts |
| 75 | Margaret Levia | 5 | daughter | — | Massachusetts |
| 76 | Elaine Levia | 4 | daughter | — | Massachusetts |
| 77 | Pauline Levia | 1 | daughter | — | Massachusetts |
| 78 | David Smith | 25 | son-in-law | Truck Driver | Massachusetts |
| 79 | Clarence Levia | 26 | brother | Truck Driver'S Assistant | Massachusetts |
| 80 | Eugene F. Willett | 45 | Head | Second Hand | Massachusetts |
Related Census Records
Pedigree Summary
William + 10 siblings
Gen 1 · 4 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)