RD
Robert Duncan — 1940 US Census Record
Model Tree available1940 United States Federal Census · Lake-County, Indiana
Our Model Tree links this Robert Duncan across the 1920, 1930 and 1940 US Censuses in Lake-County, Indiana (XGBoost, ~Confirmed), with identified parents Robert & Catherine — first a head (b.~1910), then head of a 3-person household.
Age 30
b. ~1910
Male
Head
Born: Florida
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Lake-County, Indiana |
| Surname | Duncan |
| Given Name | Robert |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 30 |
| Marital Status | Married |
| Birthplace | Florida |
| 1935 Residence (City) | Hammond |
| 1935 Residence (County) | Lake |
| Additional Details | |
| Occupation | Researcher |
| Industry | Oil Refinery |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 1260 |
| Highest Grade | No C 4 |
| 1935 Residence | Same place |
| Birth State | Florida |
| Birth Country | United States |
| Birthplace (normalized) | florida |
| Occupation | Researcher |
| Township / Ward | Hammond |
| Est. Birth Year | ~1910 |
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 Robert | Age | Birth yr |
|---|---|---|---|---|
| Susan Duncan | Daughter | — | 4 | ~1936 |
| Robert Duncan | Head | — | 30 | ~1910 |
| Eloie Duncan | Spouse | — | 29 | ~1911 |
Census Appearances
1920
Lake, Indiana
Son, age 9
Lake, Indiana · implied b. ~1911 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duncan |
| Given Name | Robert E |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 9 |
| Marital Status | Single |
| Birthplace | Florida |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Florida |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Florida |
| Birth Country | United States |
| Birthplace (normalized) | florida |
1930
Lake, Indiana
Son, age 20
Lake, Indiana · implied b. ~1910 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duncan |
| Given Name | Robert Jr. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 20 |
| Marital Status | Single |
| Birthplace | Florida |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Florida |
| Occupation | Time Keeper |
| Industry | Steel Mill |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Florida |
| Birth Country | United States |
| Birthplace (normalized) | florida |
1940
Lake-County, Indiana
Head, age 30
Lake-County, Indiana · implied b. ~1910 — 3 household members
| Surname | Duncan |
| Given Name | Robert |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 30 |
| Marital Status | Married |
| Birthplace | Florida |
| 1935 Residence (City) | Hammond |
| 1935 Residence (County) | Lake |
| Occupation | Researcher |
| Industry | Oil Refinery |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 1260 |
| Highest Grade | No C 4 |
| 1935 Residence | Same place |
| Birth State | Florida |
| Birth Country | United States |
| Birthplace (normalized) | florida |
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 Robert Duncan across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Robert Duncan (~0.92 confidence) and mother Catherine Duncan (~0.92 confidence) and mother Katherine Duncan (~0.92 confidence). The pedigree spans 1 generation with 3 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Robert Duncan
b. ~1886
Source father
● Household
· direct · ~0.92
Mother
Catherine Duncan
b. ~1889
Source mother
● Household
· direct · ~0.92
Mother
Katherine Duncan
b. ~1889
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Robert Duncan
Head · 1940 · age 30 · b. ~1910 · Indiana
★ 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 — Lake-County, Indiana
Open full size
1940 US Federal Census — Lake-County, Indiana
Page Contents
39 people indexed on this census page (nara:1940:m-t0627-01066-00470)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Helen O Patrick | 30 | Wife | — | Canada-English |
| 42 | Jeanette Patrick | 7 | Daughter | — | Indiana |
| 43 | Patricia Patrick | 1 | Daughter | — | Indiana |
| 45 | William Fuller | 63 | Head | Pipe Fitter | Indiana |
| 46 | Alice Fuller | 62 | Wife | — | Indiana |
| 47 | Leslie A. B. Miles | 48 | Head | — | Indiana |
| 48 | Irene Miles | 38 | Wife | — | Indiana |
| 49 | Albert Miles | 17 | Son | — | Indiana |
| 50 | Dorothy Miles | 11 | Daughter | — | Indiana |
| 51 | Donald Miles | 8 | Son | — | Indiana |
| 52 | Richard Miles | 6 | Son | — | Indiana |
| 53 | Mike Kamps | 47 | Head | Chipper | Hungary |
| 54 | Annie Kamps | 44 | Wife | Proprietor | Hungary |
| 55 | Mary Kamps | 18 | Daughter | — | Illinois |
| 56 | Ralph Porter | 43 | Head | Pumper | Indiana |
| 57 | Pearl Porter | 40 | Wife | — | Indiana |
| 58 | Dorothy Porter | 15 | Daughter | — | Indiana |
| 59 | Ralph Jr. Porter | 10 | Son | — | Indiana |
| 60 | James Vaughan | 62 | Head | Electrician | Kentucky |
| 61 | Laura Vaughan | 50 | Wife | — | Indiana |
| 62 | Cecil Mercer | 23 | Head | Mechanic | Indiana |
| 63 | Lillian Mercer | 19 | Wife | — | Indiana |
| 64 | Robert Lee Mercer | 1 | Son | — | Indiana |
| 65 | Irene Bishop | 13 | Sister-in-law | — | Indiana |
| 66 | Edward Cotner | 46 | Head | Pumper Helper | Indiana |
| 67 | Grace Cotner | 44 | Wife | — | Illinois |
| 68 | Richard Cotner | 19 | Son | — | Illinois |
| 69 | Euphema Cotner | 18 | Daughter | — | Indiana |
| 70 | Herbert Lee Cotner | 13 | Son | — | Indiana |
| 71 | Andrew Kowalski | 39 | Head | Service Engineer | Connecticut |
| 72 | Mary Kowalski | 43 | Wife | — | Hungary |
| 73 | Lillian Kowalski | 19 | Daughter | — | Indiana |
| 74 | Delores M. Kowalski | 9 | Daughter | — | Indiana |
| 75 | John Mehok | 37 | Head | Operator | Indiana |
| 76 | Anna Mehok | 32 | Wife | — | Indiana |
| 77 | Joseph A. Mehok | 2 | Son | — | Indiana |
| 78 | Robert Duncan THIS PERSON | 30 | Head | Researcher | Florida |
| 79 | Eloie Duncan | 29 | Wife | — | Ohio |
| 80 | Susan Duncan | 4 | Daughter | — | Illinois |
Pedigree Summary
Robert
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)