OS
Oscar Smith — 1940 US Census Record
Model Tree available1940 United States Federal Census · Johnson-County, Iowa
Our Model Tree links this Oscar Smith across the 1920, 1930 and 1940 US Censuses in Johnson-County, Iowa (XGBoost, ~Confirmed), with identified parents Delos & Oscar — first a son (b.~1906), then head of a 4-person household.
Age 34
b. ~1906
Male
Son
Born: Iowa
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Johnson-County, Iowa |
| Surname | Smith |
| Given Name | Oscar W |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 34 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Iowa City |
| 1935 Residence (County) | Johnson |
| Additional Details | |
| Occupation | Laborer |
| Industry | Farm |
| Class of Worker | PW |
| Hours Worked | 52 |
| Income (1939) | 500 |
| Highest Grade | No 8 |
| 1935 Residence | Same House |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Occupation | Laborer |
| Township / Ward | Iowa City |
| Est. Birth Year | ~1906 |
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 Oscar | Age | Birth yr |
|---|---|---|---|---|
| Oscar Smith | Head | — | 68 | ~1872 |
| John Smith | Son | — | 36 | ~1904 |
| Oscar Smith | Son | — | 34 | ~1906 |
| Anna Smith | Spouse | — | 64 | ~1876 |
Census Appearances
1920
Johnson, Iowa
Son, age 13
Johnson, Iowa · implied b. ~1907 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Smith |
| Given Name | Oscar W. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Occupation | none |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1930
Johnson, Iowa
Son, age 23
Johnson, Iowa · implied b. ~1907 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Smith |
| Given Name | Oscar W. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Iowa |
| Age at First Marriage | VAVV |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Occupation | Farm Laborer |
| Industry | General Farm |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Johnson-County, Iowa
Son, age 34
Johnson-County, Iowa · implied b. ~1906 — 4 household members
| Surname | Smith |
| Given Name | Oscar W |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 34 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Iowa City |
| 1935 Residence (County) | Johnson |
| Occupation | Laborer |
| Industry | Farm |
| Class of Worker | PW |
| Hours Worked | 52 |
| Income (1939) | 500 |
| Highest Grade | No 8 |
| 1935 Residence | Same House |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
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 Oscar Smith across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Delos Smith (~0.92 confidence) and father Oscar Smith (~0.92 confidence) and mother Anna Smith (~0.92 confidence) and mother Anna Smith (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Delos Smith
b. ~1871
Source father
● Household
· direct · ~0.92
Father
Oscar Smith
b. ~1871
Source father
● Household
· direct · ~0.92
Mother
Anna Smith
b. ~1876
Source mother
● Household
· direct · ~0.92
Mother
Anna Smith
b. ~1877
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Oscar Smith
Son · 1940 · age 34 · b. ~1906 · Iowa
★ You are viewing this record
Sibling
John Smith
Sibling · 1940 · age 36
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 — Johnson-County, Iowa
Open full size
1940 US Federal Census — Johnson-County, Iowa
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01171-00098)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Pat H O'Brien | 75 | Head | Farmer | Iowa |
| 2 | Elizabeth O'Brien | 55 | Wife | — | Iowa |
| 3 | Ralph O'Brien | 28 | Son | Assist. Manager | Iowa |
| 4 | Donald O'Brien | 17 | Son | — | Iowa |
| 5 | Jacob H Guerenberger | 49 | Head | Anatomy Tech | Iowa |
| 6 | Olga K Guerenberger | 43 | Wife | — | Missouri |
| 7 | Molly Johnson | 72 | Mother-in-law | — | Sweden |
| 8 | Merton E Tudor | 42 | Head | Mail Carrier | Iowa |
| 9 | Georgia G Tudor | 43 | Wife | — | Iowa |
| 10 | Keith M Tudor | 19 | Son | Retail | Iowa |
| 11 | Robert W Tudor | 15 | Son | — | Iowa |
| 12 | Ward R Wilkinson | 28 | Head | Farmer | Iowa |
| 13 | Clara M Wilkinson | 28 | Wife | Bookkeeper | Iowa |
| 14 | Richard Wilkinson | 9 | Son | — | Iowa |
| 15 | Henry Ruppert | 44 | Head | Farmer | Iowa |
| 16 | Helen M Ruppert | 38 | Wife | — | Iowa |
| 17 | Betty M Ruppert | 7 | Daughter | — | Iowa |
| 18 | Jacqueline Ruppert | 3 | Daughter | — | Iowa |
| 19 | Anna Alderman | 68 | Mother-in-law | — | Iowa |
| 20 | Leo Villhauer | 20 | Hired man | Hired Help | Iowa |
| 21 | Walter Reese | 23 | Hired man | Hired Help | Nebraska |
| 22 | Harry Hanson | 57 | Head | Farmer | Iowa |
| 23 | Katherine F Hanson | 54 | Wife | — | Iowa |
| 24 | Russell Stodard | 23 | Hired Help | Hired Help | Missouri |
| 25 | Oscar G Smith | 68 | Head | Farmer | Iowa |
| 26 | Anna A Smith | 64 | Wife | — | Iowa |
| 27 | John P Smith | 36 | Son | Laborer | Iowa |
| 28 | Oscar W Smith THIS PERSON | 34 | Son | Laborer | Iowa |
| 29 | Fred C Yumpa | 43 | Head | Farmer | Iowa |
| 30 | Alvina M Yumpa | 40 | Wife | — | Iowa |
| 31 | Robert D Yumpa | 12 | Son | — | Iowa |
| 32 | Mable S Yumpa | 11 | Daughter | — | Iowa |
| 33 | Paul Yumpa | 9 | Son | — | Iowa |
| 34 | Wayne F Yumpa | 3 | Son | — | Iowa |
| 35 | Afford H Trebnk | 57 | Head | Veterinary | Iowa |
| 36 | Minnie C Trebnk | 50 | Wife | — | Iowa |
| 37 | Joan H Trebnk | 17 | Daughter | — | Iowa |
| 38 | Edwin S Trebnk | 28 | Son | Engineer | Iowa |
| 39 | Mary Trebnk | 27 | Daughter | — | Iowa |
| 40 | Jerry E Trebnk | 2 | Grandchild | — | Iowa |
Pedigree Summary
Oscar + 1 sibling
Gen 1 · 4 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)