JC
John Clark — 1940 US Census Record
Model Tree available1940 United States Federal Census · Rock-Island-County, Illinois
Our Model Tree links this John Clark across the 1920, 1930 and 1940 US Censuses in Rock-Island-County, Illinois (XGBoost, ~Confirmed), with identified parents John & John — first a son (b.~1908), then head of a 3-person household.
Age 32
b. ~1908
Male
Son
Born: Wisconsin
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Rock-Island-County, Illinois |
| Surname | Clark |
| Given Name | John B. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 32 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| 1935 Residence (City) | Rock Island |
| 1935 Residence (County) | Rock Island |
| Additional Details | |
| Highest Grade | H-2 |
| 1935 Residence | Same Town |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
| Township / Ward | Rock Island |
| Est. Birth Year | ~1908 |
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 John | Age | Birth yr |
|---|---|---|---|---|
| Marguerite Clark | Daughter | — | 30 | ~1910 |
| John Clark | Head | — | 71 | ~1869 |
| John Clark | Son | — | 32 | ~1908 |
Census Appearances
1920
Rock Island, …
Son, age 12
Rock Island, Illinois · implied b. ~1908 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Clark |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| Father's Birthplace | Ireland |
| Mother's Birthplace | Iowa |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | Irish |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
1930
Rock Island, …
Son, age 22
Rock Island, Illinois · implied b. ~1908 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Clark |
| Given Name | John B. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 22 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| Father's Birthplace | Free State Ireland |
| Mother's Birthplace | Iowa |
| Occupation | Bell hop |
| Industry | Hotel |
| Class of Worker | W |
| Can Read/Write | Yes |
| Mother Tongue | English |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
1940
Rock-Island-County, Illinois
Son, age 32
Rock-Island-County, Illinois · implied b. ~1908 — 3 household members
| Surname | Clark |
| Given Name | John B. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 32 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| 1935 Residence (City) | Rock Island |
| 1935 Residence (County) | Rock Island |
| Highest Grade | H-2 |
| 1935 Residence | Same Town |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
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 Clark across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father John Clark (~0.92 confidence) and father John Clark (~0.92 confidence) and father John Clark (~0.92 confidence) and mother Alma Clark (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
John Clark
b. ~1869
Source father
● Household
· direct · ~0.92
Father
John Clark
b. ~1870
Source father
● Household
· direct · ~0.92
Father
John Clark
b. ~1869
Source father
● Household
· direct · ~0.92
Mother
Alma Clark
b. ~1873
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Clark
Son · 1940 · age 32 · b. ~1908 · Illinois
★ You are viewing this record
Sibling
Marguerite Clark
Sibling · 1940 · age 30
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 — Rock-Island-County, Illinois
Open full size
1940 US Federal Census — Rock-Island-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00877-00189)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Judith Ann Magnuson | 1 | Daughter | — | Illinois |
| 42 | Elwood Baker | 45 | Head | Checker | Illinois |
| 43 | Adelia Baker | 46 | Wife | — | Iowa |
| 44 | Howard Baker | 16 | Son | — | Iowa |
| 45 | Cora Baker | 14 | Daughter | — | Iowa |
| 46 | James Baker | 12 | Son | — | Illinois |
| 47 | Maude Rooney | 56 | Head | Domestic | Iowa |
| 48 | Etta Cook | 83 | Mother | — | Iowa |
| 49 | Jacob Scheffe | 44 | Head | Sheet Metal Worker | Illinois |
| 50 | Louisa Scheffe | 50 | Wife | — | Iowa |
| 51 | Lawrence Johnson | 64 | Head | — | Illinois |
| 52 | Rose Johnson | 61 | Wife | — | Nebraska |
| 53 | Jacob Canum | 52 | Head | Tool Maker | Kansas |
| 54 | May Canum | 46 | Wife | — | Illinois |
| 55 | Mark Canum | 23 | Son | Draftsman | Illinois |
| 56 | Eva Canum | 10 | Daughter | — | Illinois |
| 57 | Doris Canum | 7 | Daughter | — | Illinois |
| 58 | Leo Ingold | 50 | Head | Bus Operator | Missouri |
| 59 | Mary Ingold | 39 | Wife | — | Illinois |
| 60 | Dorothea Ingold | 12 | Daughter | — | Illinois |
| 61 | Eva Stone | 31 | Lodger | Attendant | Illinois |
| 62 | Harley C. Sargent | 55 | Head | Crane Tender | Illinois |
| 63 | Faye Sargent | 53 | Wife | — | Wisconsin |
| 64 | Hazel Sargent | 28 | Daughter | Sewing Machine Operator | Illinois |
| 65 | Olive Young | 35 | Sister-in-law | Dietitian | Wisconsin |
| 66 | Regina Young | 17 | Niece | — | Illinois |
| 67 | Grace Hiner | 41 | Head | — | Indiana |
| 68 | Victor De Cock | 51 | Lodger | Cement Finisher | Belgium |
| 69 | John H. Clark | 71 | Head | Flagman | England |
| 70 | John B. Clark THIS PERSON | 32 | Son | — | Wisconsin |
| 71 | Marguerite Clark | 30 | Daughter | — | Wisconsin |
| 72 | Joseph Massagli | 30 | Head | Core Maker | Iowa |
| 73 | Helen Massagli | 24 | Wife | — | Iowa |
| 74 | Joan Massagli | 6 | Daughter | — | Iowa |
| 75 | Johnny Massagli | 4 | Son | — | Iowa |
| 76 | Anna Williams | 62 | Head | — | Illinois |
| 77 | Edna Stevens | 30 | Lodger | Laster | Canada |
| 78 | Joseph Havens | 52 | Lodger | Dish Washer | Illinois |
| 79 | Luella Burghart | 49 | Head | — | Kansas |
| 80 | William Burghart | 15 | Son | — | Illinois |
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)