JD
James Duffy — 1940 US Census Record
Model Tree available1940 United States Federal Census · San-Francisco-County, California
Our Model Tree links this James Duffy across the 1920, 1930 and 1940 US Censuses in San-Francisco-County, California (XGBoost, ~Confirmed), with identified parents Mathew & Annie — first a son (b.~1918), then head of a 5-person household.
Age 22
b. ~1918
Male
Son
Born: California
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | San-Francisco-County, California |
| Surname | Duffy |
| Given Name | James V. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 22 |
| Marital Status | Single |
| Birthplace | California |
| 1935 Residence (City) | San Francisco |
| 1935 Residence (County) | San Francisco |
| Additional Details | |
| Occupation | Clerk |
| Industry | Transfer Co |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 720 |
| Highest Grade | H 4 |
| 1935 Residence | Same Place |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
| Occupation | Clerk |
| Township / Ward | San Francisco |
| Est. Birth Year | ~1918 |
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.
5 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to James | Age | Birth yr |
|---|---|---|---|---|
| Bernice Duffy | Daughter | — | 28 | ~1912 |
| Mathew Duffy | Head | — | 61 | ~1879 |
| James Duffy | Son | — | 22 | ~1918 |
| Donald Duffy | Son | — | 18 | ~1922 |
| Annie Duffy | Spouse | — | 50 | ~1890 |
Census Appearances
1920
San Francisco, …
Son, age 2
San Francisco, California · implied b. ~1918 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | James |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 2 |
| Marital Status | Single |
| Birthplace | California |
| Father's Birthplace | California |
| Mother's Birthplace | California |
| Speaks English | Yes |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
1930
San Francisco, …
Son, age 12
San Francisco, California · implied b. ~1918 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | James |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | California |
| Father's Birthplace | California |
| Mother's Birthplace | California |
| Can Read/Write | Yes |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
1940
San-Francisco-County, California
Son, age 22
San-Francisco-County, California · implied b. ~1918 — 5 household members
| Surname | Duffy |
| Given Name | James V. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 22 |
| Marital Status | Single |
| Birthplace | California |
| 1935 Residence (City) | San Francisco |
| 1935 Residence (County) | San Francisco |
| Occupation | Clerk |
| Industry | Transfer Co |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 720 |
| Highest Grade | H 4 |
| 1935 Residence | Same Place |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
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 James Duffy across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Mathew Duffy (~0.92 confidence) and mother Annie Duffy (~0.92 confidence) and father John Duffy (~0.92 confidence) and mother Margaret Duffy (~0.92 confidence) and mother Gertrude Duffy (~0.92 confidence). The pedigree spans 1 generation with 5 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Mathew Duffy
b. ~1879
Source father
● Household
· direct · ~0.92
Mother
Annie Duffy
b. ~1890
Source mother
● Household
· direct · ~0.92
Father
John Duffy
b. ~1890
Source father
● Household
· direct · ~0.92
Mother
Margaret Duffy
b. ~1893
Source mother
● Household
· direct · ~0.92
Mother
Gertrude Duffy
b. ~1894
Source mother
● Household
· direct · ~0.92
This person
Anchor record
James Duffy
Son · 1940 · age 22 · b. ~1918 · California
★ You are viewing this record
Sibling
Bernice Duffy
Sibling · 1940 · age 28
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Donald Duffy
Sibling · 1940 · age 18
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 — San-Francisco-County, California
Open full size
1940 US Federal Census — San-Francisco-County, California
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00316-00007)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Thomas E. Lundy | 28 | Head | Accounting Clerk | Montana |
| 42 | Irene A. Lundy | 33 | Wife | — | Montana |
| 43 | Mathew X. Duffy | 61 | Head | Mechanic | Irish Free State |
| 44 | Annie M. Duffy | 50 | Wife | — | Irish Free State |
| 45 | Bernice A. Duffy | 28 | Daughter | Sub Teacher | California |
| 46 | James V. Duffy THIS PERSON | 22 | Son | Clerk | California |
| 47 | Donald P. Duffy | 18 | Son | Clerk | California |
| 48 | Herbert E. Hanlon | 54 | Head | News Writer | Massachusetts |
| 49 | Mary E. Hanlon | 52 | Wife | — | Minnesota |
| 50 | Alexander O. Schmidt | 84 | Head | Chemist | Germany |
| 51 | Helen M. Schmidt | 73 | Wife | — | California |
| 52 | Marie Gofober | 48 | Housekeeper | Housekeeper | Germany |
| 53 | Blanche Partington | 72 | Head | Practitioner | England |
| 54 | Hermon O. Albright | 62 | Brother-in-law | Artist | Germany |
| 55 | Gertrude P. Albright | 62 | Wife | Instructor | England |
| 56 | Evelyn Albright | 27 | Daughter | — | California |
| 57 | Herbert Maxwell | 53 | Head | — | California |
| 58 | Lucille A. Maxwell | 38 | Wife | Clerk | Chicago |
| 59 | Jere D. Maxwell | 8 | Son | — | California |
| 60 | Betty A. Maxwell | 3 | Daughter | — | California |
| 61 | Lila Maxwell | 65 | Sister | — | California |
| 62 | Charles W. Strobel | 68 | Head | Manager | California |
| 63 | Silvia P. Strobel | 63 | Wife | — | California |
| 64 | Edward T. Hewitt | 27 | Head | Salesman | California |
| 65 | Viola K. Hewitt | 31 | Wife | — | California |
| 66 | Annie S. Thompson | 47 | Head | Artist Commercial | California |
| 67 | Nellie B. Thompson | 79 | Mother | — | Iowa |
| 68 | Erma Bahre | 44 | Head | Teacher | California |
| 69 | Leola R. Martins | 49 | Head | Store Mgr. | California |
| 70 | Jack W. Martins | 20 | Son | — | California |
| 71 | Bob A. Martins | 15 | Son | — | California |
| 72 | Therese Brunings | 72 | Mother | — | California |
| 73 | Margaret T. Austin | 79 | Head | — | California |
| 74 | Sami I. Hori | 53 | Head | Housework | Japan |
| 75 | Emi Hori | 51 | Wife | Housework | Japan |
| 76 | Edna P. Wilsey | 63 | Head | — | California |
| 77 | James R. Sr. Wilsey | 36 | Son | Contractor | Mexico |
| 78 | Alice C. Wilsey | 35 | Daughter-in-law | Clerk | California |
| 79 | James R. Jr. Wilsey | 10 | Grandson | — | California |
| 80 | Helen E. Wilsey | 7 | Granddaughter | — | California |
Pedigree Summary
James + 2 siblings
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)