MD
Mary Duncan — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Vermilion-County, Illinois
Our Model Tree links this Mary Duncan across the 1920, 1930 and 1940 US Censuses in Vermilion-County, Illinois (XGBoost, ~Confirmed) — first a spouse (b.~1891), then head of a 3-person household.
Age 49
b. ~1891
Female
Spouse
Born: Illinois
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Vermilion-County, Illinois |
| Surname | Duncan |
| Given Name | Mary E. |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 49 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Potomac Village |
| 1935 Residence (County) | Vermilion |
| Additional Details | |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Potomac Village |
| Est. Birth Year | ~1891 |
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 |
|---|---|---|---|---|
| Fred Duncan | Head | — | 54 | ~1886 |
| Lewis Duncan | Son | — | 16 | ~1924 |
| Mary Duncan | Spouse | — | 49 | ~1891 |
Census Appearances
1920
Vermilion, Illinois
Spouse, age 29
Vermilion, Illinois · implied b. ~1891 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duncan |
| Given Name | Mary E |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 29 |
| Marital Status | Married |
| Birthplace | Illinois |
| Father's Birthplace | Indiana |
| Mother's Birthplace | Ohio |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1930
Vermilion, Illinois
Spouse, age 39
Vermilion, Illinois · implied b. ~1891 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duncan |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 39 |
| Marital Status | Married |
| Birthplace | Illinois |
| Age at First Marriage | 24 |
| Father's Birthplace | Indiana |
| Mother's Birthplace | Ohio |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Vermilion-County, Illinois
Spouse, age 49
Vermilion-County, Illinois · implied b. ~1891 — 3 household members
| Surname | Duncan |
| Given Name | Mary E. |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 49 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Potomac Village |
| 1935 Residence (County) | Vermilion |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
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 Duncan across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Duncan
Spouse · 1940 · age 49 · b. ~1891 · Illinois
★ 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 — Vermilion-County, Illinois
Open full size
1940 US Federal Census — Vermilion-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00899-00448)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Caroline Swisher | 77 | Head | — | Illinois |
| 42 | Johnson Miles | 72 | Head | — | Ohio |
| 43 | Emma Knott | 68 | Head | — | Illinois |
| 44 | Mary A. Henry | 78 | Head | — | Illinois |
| 45 | Frank H. Henry | 82 | Head | — | Indiana |
| 46 | Emma V. Wilson | 78 | Head | — | Virginia |
| 47 | Fred F. Jameson | 66 | Head | Caretaker | Illinois |
| 48 | Ida M. Jameson | 64 | Wife | — | Illinois |
| 49 | Charles H. Moreland | 62 | Head | Insurance Agt | Illinois |
| 50 | Estella T. Moreland | 53 | Wife | — | Illinois |
| 51 | Virginia Moreland | 19 | Daughter | — | Illinois |
| 52 | Edmund P. Butz | 34 | Head | School Teacher | Illinois |
| 53 | Clara L. Butz | 26 | Wife | Beauty Operator | Illinois |
| 54 | Everett W. Wilson | 56 | Head | State Clerk | Illinois |
| 55 | Bessie T. Wilson | 54 | Wife | — | Illinois |
| 56 | Margaret V. Wilson | 29 | Daughter | School Teacher | Illinois |
| 57 | Fred S. Osborne | 77 | Head | — | Illinois |
| 58 | Laura L. Osborne | 69 | Wife | — | Illinois |
| 59 | Harriet A. Elliot | 68 | Head | Housekeeper | Illinois |
| 60 | Susan Goodwin | 89 | Head | — | Ohio |
| 61 | Thomas Mclouder | 63 | Head | Digging Ditch | Iowa |
| 62 | Sylvia C. Mclouder | 58 | Wife | Napping Dirt | Illinois |
| 63 | Cassie Sellers | 65 | Head | — | Illinois |
| 64 | Elizabeth P. Sellers | 57 | Wife | — | Illinois |
| 65 | Nadoy M. Sellers | 22 | Son | New Worker | Illinois |
| 66 | Lulu H. Downing | 37 | Daughter | School Teacher | Illinois |
| 67 | Thomas A. Downing | 1 | Grandson | — | Illinois |
| 68 | James E. Redman | 67 | Head | — | Ohio |
| 69 | Anna A. Redman | 64 | Wife | — | Illinois |
| 70 | Leland Jameson | 39 | Head | Painter & Paper H. | Illinois |
| 71 | Hilda Jameson | 34 | Wife | Clerk | Illinois |
| 72 | Benj. F. Morgan | 47 | Head | Publisher | Illinois |
| 73 | Irah M. Morgan | 36 | Wife | Asst Publisher | Illinois |
| 74 | Cora A. Scott | 49 | Head | — | Illinois |
| 75 | Emma A. Scott | 22 | Daughter | Asst Postmaster | Illinois |
| 76 | Mildred J. Scott | 20 | Daughter | — | Illinois |
| 77 | Fred W. Duncan | 54 | Head | Hardware & Implement Dealer | Illinois |
| 78 | Mary E. Duncan THIS PERSON | 49 | Wife | — | Illinois |
| 79 | Lewis F. Duncan | 16 | Son | — | Illinois |
| 80 | William S. Corwin | 70 | Head | Medical Doctor | Illinois |
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)