JG
John Grace — 1940 US Census Record
Model Tree available1940 United States Federal Census · Dubuque-County, Iowa
Our Model Tree links this John Grace across the 1920, 1930 and 1940 US Censuses in Dubuque-County, Iowa (XGBoost, ~Confirmed), with identified parents John & John — first a son (b.~1917), then head of a 4-person household.
Age 23
b. ~1917
Male
Son
Born: Iowa
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Dubuque-County, Iowa |
| Surname | Grace |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (County) | Dubuque |
| Additional Details | |
| Occupation | Farming |
| Industry | NP |
| Class of Worker | 333 |
| Highest Grade | No 8 |
| 1935 Residence | 70 |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Occupation | Farming |
| Township / Ward | Vernon Township |
| Est. Birth Year | ~1917 |
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 |
|---|---|---|---|---|
| John Grace | Son | — | 23 | ~1917 |
| William Kupferschmidt | Other | — | 58 | ~1882 |
| Martha Grace | Head | — | 73 | ~1867 |
| Gerald Grace | Son | — | 21 | ~1919 |
Census Appearances
1920
Dubuque, Iowa
Son, age 3
Dubuque, Iowa · implied b. ~1917 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Grace |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 3 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1930
Dubuque, Iowa
Son, age 13
Dubuque, Iowa · implied b. ~1917 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Grace |
| Given Name | John J. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Can Read/Write | Yes |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Dubuque-County, Iowa
Son, age 23
Dubuque-County, Iowa · implied b. ~1917 — 4 household members
| Surname | Grace |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (County) | Dubuque |
| Occupation | Farming |
| Industry | NP |
| Class of Worker | 333 |
| Highest Grade | No 8 |
| 1935 Residence | 70 |
| 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 John Grace across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father John Grace (~0.92 confidence) and father John Grace (~0.92 confidence) and mother Martha Grace (~0.92 confidence) and mother Nellie Grace (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
John Grace
b. ~1894
Source father
● Household
· direct · ~0.92
Father
John Grace
b. ~1876
Source father
● Household
· direct · ~0.92
Mother
Martha Grace
b. ~1867
Source mother
● Household
· direct · ~0.92
Mother
Nellie Grace
b. ~1887
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Grace
Son · 1940 · age 23 · b. ~1917 · Iowa
★ You are viewing this record
Sibling
Gerald Grace
Sibling · 1940 · age 21
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 — Dubuque-County, Iowa
Open full size
1940 US Federal Census — Dubuque-County, Iowa
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01159-00713)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Michael O'Brien | 3 | Son | — | Iowa |
| 42 | Joseph O'Brien | 1 | Son | — | Iowa |
| 43 | Bernice Callahan | 21 | Maid | Domestic | Iowa |
| 44 | Martha Grace | 73 | Head | Farming | Iowa |
| 45 | John Grace THIS PERSON | 23 | Son | Farming | Iowa |
| 46 | Gerald Grace | 21 | Son | Farming | Iowa |
| 47 | William Kupferschmidt | 58 | Lodger | Farm Hand | Iowa |
| 48 | James J Flynn | 67 | Head | Farming | Iowa |
| 49 | James E Flynn | 36 | Son | Farming | Iowa |
| 50 | Thomas A Flynn | 34 | Son | Farming | Iowa |
| 51 | Frank Murphy | 65 | Head | Farming | Iowa |
| 52 | Catherine Murphy | 69 | Wife | — | Iowa |
| 53 | Bernard Murphy | 34 | Son | Farming | Iowa |
| 54 | Mary Murphy | 28 | Daughter | — | Iowa |
| 55 | George Quirk | 58 | Head | Farming | Iowa |
| 56 | Mary Quirk | 58 | Wife | — | Iowa |
| 57 | Marcella Quirk | 27 | Daughter | — | Iowa |
| 58 | Donald Quirk | 5 | Grandson | — | Iowa |
| 59 | Earl Hartman | 44 | Head | Farming | Iowa |
| 60 | Bernadine Hartman | 26 | Wife | — | Iowa |
| 61 | David Hartman | 5 | Son | — | Iowa |
| 62 | Walter Hartman | 3 | Son | — | Iowa |
| 63 | Laverne Hartman | 1 | Son | — | Iowa |
| 64 | Howard Hartman | 32 | Head | Farming | Iowa |
| 65 | Susan Hartman | 32 | Wife | — | Iowa |
| 66 | Paul Hartman | 9 | Son | — | Iowa |
| 67 | Kenneth Hartman | 7 | Son | — | Iowa |
| 68 | Wilbur Hartman | 5 | Son | — | Iowa |
| 69 | Shirley Hartman | 2 | Daughter | — | Iowa |
| 70 | Rita Hartman | 1 | Daughter | — | Iowa |
| 71 | Harold Bartels | 34 | Head | Farmer | Iowa |
| 72 | Lorene Bartels | 28 | Wife | — | Iowa |
| 73 | Shirley Ann Bartels | 4 | Daughter | — | Iowa |
| 74 | Merlin Bartels | 1 | Son | — | Iowa |
| 75 | Joseph A Siegert | 51 | Head | Farming | Iowa |
| 76 | Clara Siegert | 48 | Wife | — | Wisconsin |
| 77 | Earl Siegert | 24 | Son | Farming | Iowa |
| 78 | Joseph Jr Siegert | 18 | Son | Farming | Iowa |
| 79 | Eileen Siegert | 16 | Daughter | — | Iowa |
| 80 | Edna Siegert | 11 | Daughter | — | Iowa |
Pedigree Summary
John + 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)