RD
Robert Duncan — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Beadle-County, South Dakota
Our Model Tree links this Robert Duncan across the 1930 and 1940 US Censuses in Beadle-County, South Dakota (XGBoost, ~Confirmed) — first a son (b.~1927), then head of a 10-person household.
Age 13
b. ~1927
Male
Son
Born: South Dakota
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Beadle-County, South Dakota |
| Surname | Duncan |
| Given Name | Robert |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | South Dakota |
| 1935 Residence (City) | Morningside Addition |
| Additional Details | |
| Highest Grade | 7 |
| Birth State | South Dakota |
| Birth Country | United States |
| Birthplace (normalized) | south dakota |
| Township / Ward | Morningside Addition |
| Est. Birth Year | ~1927 |
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.
10 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Robert | Age | Birth yr |
|---|---|---|---|---|
| Darlene Duncan | Daughter | — | 12 | ~1928 |
| Duane Duncan | Son | — | 5 | ~1935 |
| Ines Duncan | Daughter | — | 1 | ~1939 |
| Wilbur Duncan | Son | — | 10 | ~1930 |
| Velores Duncan | Daughter | — | 8 | ~1932 |
| Annie Duncan | Spouse | — | 40 | ~1900 |
| Roy Duncan | Head | — | 43 | ~1897 |
| Oscar Duncan | Son | — | 18 | ~1922 |
| Norman Duncan | Son | — | 14 | ~1926 |
| Robert Duncan | Son | — | 13 | ~1927 |
Census Appearances
1930
Beadle, South …
Son, age 3
Beadle, South Dakota · implied b. ~1927 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duncan |
| Given Name | Robert W |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 3 |
| Marital Status | Single |
| Birthplace | South Dakota |
| Father's Birthplace | Nebraska |
| Mother's Birthplace | South Dakota |
| Birth State | South Dakota |
| Birth Country | United States |
| Birthplace (normalized) | south dakota |
1940
Beadle-County, South …
Son, age 13
Beadle-County, South Dakota · implied b. ~1927 — 10 household members
| Surname | Duncan |
| Given Name | Robert |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | South Dakota |
| 1935 Residence (City) | Morningside Addition |
| Highest Grade | 7 |
| Birth State | South Dakota |
| Birth Country | United States |
| Birthplace (normalized) | south dakota |
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 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Robert Duncan
Son · 1940 · age 13 · b. ~1927 · South Dakota
★ You are viewing this record
Sibling
Norman Duncan
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Wilbur Duncan
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Velores Duncan
Sibling · 1940 · age 8
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Darlene Duncan
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Duane Duncan
Sibling · 1940 · age 5
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Oscar Duncan
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Ines Duncan
Sibling · 1940 · age 1
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 — Beadle-County, South Dakota
Open full size
1940 US Federal Census — Beadle-County, South Dakota
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03847-00299)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Gloria Engbretson | 4 | Daughter | — | South Dakota |
| 42 | Iren Engbretson | 3 | Daughter | — | South Dakota |
| 43 | Emma V. Harvey | 71 | Head | Store Keeper | Iowa |
| 44 | Clarence Engbretson | 26 | Head | Common Laborer | North Dakota |
| 45 | Viola Engbretson | 20 | Wife | — | South Dakota |
| 46 | Ted Peery | 26 | Head | Wpa | South Dakota |
| 47 | Evelyn D. Peery | 25 | Wife | — | South Dakota |
| 48 | Nila Peery | 4 | Daughter | — | South Dakota |
| 49 | Edward Peery | 3 | Son | — | South Dakota |
| 50 | Donald Peery | 0 | Son | — | South Dakota |
| 51 | Bert Bates | 45 | Head | — | Iowa |
| 52 | Mary Bates | 39 | Wife | — | South Dakota |
| 53 | Anne Joy Bates | 11 | Daughter | — | South Dakota |
| 54 | Joseph Bates | 9 | Son | — | South Dakota |
| 55 | Luther Bates | 7 | Son | — | South Dakota |
| 56 | William Tillison | 55 | Head | Wpa | Iowa |
| 57 | Minnie Tillison | 32 | Wife | — | Iowa |
| 58 | Ruby Tillison | 11 | Daughter | — | South Dakota |
| 59 | Robert Baum | 62 | Head | Wpa | South Dakota |
| 60 | Emma D. Baum | 50 | Wife | — | Nebraska |
| 61 | Roy Duncan | 43 | Head | Armour Plant | Nebraska |
| 62 | Annie Duncan | 40 | Wife | — | South Dakota |
| 63 | Oscar Duncan | 18 | Son | Ccc | North Dakota |
| 64 | Norman Duncan | 14 | Son | — | South Dakota |
| 65 | Robert Duncan THIS PERSON | 13 | Son | — | South Dakota |
| 66 | Darlene Duncan | 12 | Daughter | — | South Dakota |
| 67 | Wilbur Duncan | 10 | Son | — | South Dakota |
| 68 | Velores Duncan | 8 | Daughter | — | South Dakota |
| 69 | Duane Duncan | 5 | Son | — | South Dakota |
| 70 | Ines Duncan | 1 | Daughter | — | South Dakota |
| 71 | Donald Lambert | 25 | Head | Wpa | South Dakota |
| 72 | Mabel Lambert | 23 | Wife | — | South Dakota |
| 73 | Irene Mae Lambert | 3 | Daughter | — | South Dakota |
| 74 | George D. Raynor | 54 | Head | Wpa | Iowa |
| 75 | Maybel Raynor | 36 | Wife | — | Maine |
| 76 | Eugene Raynor | 4 | Son | — | South Dakota |
| 77 | Madeline Raynor | 2 | Daughter | — | South Dakota |
| 78 | Frank S. Jr. Curtis | 66 | Head | — | Maine |
| 79 | Blanch Curtis | 64 | Wife | — | Maine |
| 80 | Guy Curtis | 35 | Son | Armour Packing | Maine |
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)