JD
John Duffy — 1940 US Census Record
Model Tree available1940 United States Federal Census · Denver-County, Colorado
Our Model Tree links this John Duffy across the 1910, 1920, 1930 and 1940 US Censuses in Denver-County, Colorado (XGBoost, ~Confirmed), with identified parents James & Ella — first a head (b.~1898), then head of a 4-person household.
Age 42
b. ~1898
Male
Head
Born: Colorado
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Denver-County, Colorado |
| Surname | Duffy |
| Given Name | John E. |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 42 |
| Marital Status | Married |
| Birthplace | Colorado |
| 1935 Residence (City) | City & County of Denver |
| 1935 Residence (County) | Denver |
| Additional Details | |
| Industry | Clerk |
| Class of Worker | Banking |
| Hours Worked | 42 |
| Highest Grade | 8 |
| 1935 Residence | Same Place |
| Birth State | Colorado |
| Birth Country | United States |
| Birthplace (normalized) | colorado |
| Township / Ward | City County Of Denver |
| Est. Birth Year | ~1898 |
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.
4 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Marjory Duffy | Daughter | — | 18 | ~1922 |
| John Duffy | Head | — | 42 | ~1898 |
| John Duffy | Son | — | 16 | ~1924 |
| Viola Duffy | Spouse | — | 39 | ~1901 |
Census Appearances
1910
Denver, Colorado
Son, age 12
Denver, Colorado · implied b. ~1898 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | John |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Colorado |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Wisconsin |
| Occupation | none |
| Birth State | Colorado |
| Birth Country | United States |
| Birthplace (normalized) | colorado |
1920
Denver, Colorado
Son, age 22
Denver, Colorado · implied b. ~1898 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | John E. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 22 |
| Marital Status | Single |
| Birthplace | Colorado |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Wisconsin |
| Occupation | Clerk |
| Industry | Railroad |
| Class of Worker | W |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Colorado |
| Birth Country | United States |
| Birthplace (normalized) | colorado |
1930
Denver, Colorado
Head, age 32
Denver, Colorado · implied b. ~1898 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | John E. |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 32 |
| Marital Status | Married |
| Birthplace | Colorado |
| Age at First Marriage | 23 |
| Father's Birthplace | Kansas |
| Mother's Birthplace | Illinois |
| Occupation | Transit Clerk |
| Industry | Bank |
| Class of Worker | W |
| Can Read/Write | Yes |
| Home Owned/Rented | O |
| Home Value / Rent | 4000 |
| Radio Set | R |
| Veteran | Yes |
| Birth State | Colorado |
| Birth Country | United States |
| Birthplace (normalized) | colorado |
1940
Denver-County, Colorado
Head, age 42
Denver-County, Colorado · implied b. ~1898 — 4 household members
| Surname | Duffy |
| Given Name | John E. |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 42 |
| Marital Status | Married |
| Birthplace | Colorado |
| 1935 Residence (City) | City & County of Denver |
| 1935 Residence (County) | Denver |
| Industry | Clerk |
| Class of Worker | Banking |
| Hours Worked | 42 |
| Highest Grade | 8 |
| 1935 Residence | Same Place |
| Birth State | Colorado |
| Birth Country | United States |
| Birthplace (normalized) | colorado |
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 4 US Census years (1910, 1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father James Duffy (~0.92 confidence) and mother Ella Duffy (~0.92 confidence) and mother Clara Duffy (~0.92 confidence). The pedigree spans 1 generation with 3 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
James Duffy
b. ~1862
Source father
● Household
· direct · ~0.92
Mother
Ella Duffy
b. ~1866
Source mother
● Household
· direct · ~0.92
Mother
Clara Duffy
b. ~1869
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Duffy
Head · 1940 · age 42 · b. ~1898 · Colorado
★ 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 — Denver-County, Colorado
Open full size
1940 US Federal Census — Denver-County, Colorado
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00488-00518)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Gertrude H. Gould | 51 | Head | — | New York |
| 42 | Frank L. Gould | 16 | Son | 50 | New York |
| 43 | Henry D. Bender | 24 | Son | — | Indiana |
| 44 | Gertrude Bender | 21 | Daughter-in-law | — | New York |
| 45 | Alva C. Jr. Ellis | 37 | Head | — | Same Place |
| 46 | Helen M. Ellis | 33 | Wife | — | Nebraska |
| 47 | James P. Ellis | 12 | Son | — | Wyoming |
| 48 | Irvin Ellis | 40 | Head | — | Colorado |
| 49 | Lillian E. Ellis | 37 | Wife | — | Colorado |
| 50 | William O. Ellis | 16 | Son | — | Colorado |
| 51 | Mary F. Ellis | 11 | Daughter | — | Colorado |
| 52 | Alfonso E. Martinez | 42 | Head | — | Colorado |
| 53 | Maria T. Martinez | 34 | Wife | — | Colorado |
| 54 | Alfonso L. Martinez | 8 | Son | — | Colorado |
| 55 | Maria C. Martinez | 6 | Daughter | — | Colorado |
| 56 | Dolores M. Martinez | 2 | Daughter | — | Colorado |
| 57 | Patricia A. Martinez | 0 | Daughter | — | Colorado |
| 58 | Lester W. Waterman | 32 | Head | — | So. Dakota |
| 59 | Leona W. Waterman | 32 | Wife | — | Colorado |
| 60 | Gerald A. Waterman | 22 | Brother | — | Nebraska |
| 61 | Claud O. Madgy | 63 | Head | 10 | Missouri |
| 62 | Julia M. Madgy | 61 | Wife | — | Missouri |
| 63 | Willis L. Tierman | 59 | Head | — | Colorado |
| 64 | Bena S. Tierman | 57 | Wife | — | Colorado |
| 65 | Homer J. Harlan | 35 | Head | — | Iowa |
| 66 | Edna S. Harlan | 36 | Wife | — | Iowa |
| 67 | John R. Harlan | 2 | Son | — | Colorado |
| 68 | Richard S. Harlan | 0 | Son | — | Colorado |
| 69 | Dolores Buelo | 20 | Servant | — | Wisconsin |
| 70 | Fred H. Carlson | 28 | Head | — | New York |
| 71 | Marie L. Carlson | 26 | Wife | — | Illinois |
| 72 | Cynthia Carlson | 1 | Daughter | — | Colorado |
| 73 | John E. Duffy THIS PERSON | 42 | Head | — | Colorado |
| 74 | Viola R. Duffy | 39 | Wife | — | Colorado |
| 75 | Marjory Ann Duffy | 18 | Daughter | — | Colorado |
| 76 | John E. Jr. Duffy | 16 | Son | — | Colorado |
| 77 | Milton N. Tobias | 28 | Head | — | Colorado |
| 78 | Flora Ann Tobias | 27 | Wife | — | Colorado |
| 79 | Elaine Esther Tobias | 4 | Daughter | — | Colorado |
| 80 | Charles J. Mcslone | 34 | Head | — | Nebraska |
Pedigree Summary
John
Gen 1 · 3 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)