JC
John Clarke — 1940 US Census Record
Model Tree available1940 United States Federal Census · Polk-County, Iowa
Our Model Tree links this John Clarke across the 1920, 1930 and 1940 US Censuses in Polk-County, Iowa (XGBoost, ~Confirmed), with identified parents Garret & Delfa — first a head (b.~1903), then head of a 5-person household.
Age 37
b. ~1903
Male
Head
Born: Missouri
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Polk-County, Iowa |
| Surname | Clarke |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 37 |
| Marital Status | Married |
| Birthplace | Missouri |
| 1935 Residence (City) | Des Moines City |
| 1935 Residence (County) | Polk |
| Additional Details | |
| Occupation | Stationary Engineer |
| Industry | Fuel & Heat Company |
| Class of Worker | OA |
| Hours Worked | 48 |
| Income (1939) | 2273 |
| Highest Grade | Hs 3 |
| 1935 Residence | Same place |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
| Occupation | Stationary Engineer |
| Township / Ward | Des Moines City |
| Est. Birth Year | ~1903 |
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.
5 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Doris Clarke | Spouse | — | 33 | ~1907 |
| Marilyn Clarke | Daughter | — | 2 | ~1938 |
| Jack Clarke | Son | — | 13 | ~1927 |
| John Clarke | Head | — | 37 | ~1903 |
| Gerald Clarke | Son | — | 9 | ~1931 |
Census Appearances
1920
Polk, Iowa
Son, age 16
Polk, Iowa · implied b. ~1904 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Clark |
| Given Name | John |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 16 |
| Marital Status | Single |
| Birthplace | Missouri |
| Father's Birthplace | Missouri |
| Mother's Birthplace | Indiana |
| Occupation | Laborer |
| Industry | Thresh mach co |
| Class of Worker | W |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
Head, age 26
Polk, Iowa · implied b. ~1904 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Clark |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 26 |
| Marital Status | Married |
| Birthplace | Missouri |
| Age at First Marriage | 21 |
| Father's Birthplace | Missouri |
| Mother's Birthplace | Missouri |
| Occupation | Electrician |
| Industry | Oil Burner |
| Class of Worker | W |
| Can Read/Write | Yes |
| Home Owned/Rented | R |
| Home Value / Rent | 25 |
| Radio Set | R |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
1940
Polk-County, Iowa
Head, age 37
Polk-County, Iowa · implied b. ~1903 — 5 household members
| Surname | Clarke |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 37 |
| Marital Status | Married |
| Birthplace | Missouri |
| 1935 Residence (City) | Des Moines City |
| 1935 Residence (County) | Polk |
| Occupation | Stationary Engineer |
| Industry | Fuel & Heat Company |
| Class of Worker | OA |
| Hours Worked | 48 |
| Income (1939) | 2273 |
| Highest Grade | Hs 3 |
| 1935 Residence | Same place |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
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 Clarke across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Garret Clark (~0.92 confidence) and mother Delfa Clark (~0.92 confidence). The pedigree spans 1 generation with 2 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Garret Clark
b. ~1879
Source father
● Household
· direct · ~0.92
Mother
Delfa Clark
b. ~1880
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Clarke
Head · 1940 · age 37 · b. ~1903 · Iowa
★ 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 — Polk-County, Iowa
Open full size
1940 US Federal Census — Polk-County, Iowa
Page Contents
39 people indexed on this census page (nara:1940:m-t0627-01193-00402)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | John Clarke THIS PERSON | 37 | Head | Stationary Engineer | Missouri |
| 42 | Doris Clarke | 33 | Wife | — | Iowa |
| 43 | Jack Clarke | 13 | Son | — | Iowa |
| 44 | Gerald Clarke | 9 | Son | — | Iowa |
| 45 | Marilyn Clarke | 2 | Daughter | — | Iowa |
| 46 | Richard Grumia | 23 | Head | Truck Driver | Iowa |
| 47 | Margery Grumia | 22 | Wife | — | Iowa |
| 48 | Wallace Shaffer | 40 | Head | Substation Clerk | Iowa |
| 49 | Kathryn Shaffer | 33 | Wife | — | Missouri |
| 50 | Ellsworth Shaffer | 4 | Son | — | Iowa |
| 51 | Andrew Shaffer | 1 | Daughter | — | Iowa |
| 52 | Julius A. Anderson | 46 | Head | Salesman | Iowa |
| 53 | Edna Mae Anderson | 48 | Wife | Librarian | Nebraska |
| 54 | Extra Lines Anderson | None | — | — | — |
| 56 | Electa Fink | 45 | Head | Supervisor Of Cost | Iowa |
| 57 | H. Horton Fink | 25 | Son | Accountant | Montana |
| 58 | Katharine Fink | 21 | Daughter | Saleslady | Iowa |
| 59 | Helen Fink | 18 | Daughter | Bookkeeper | Iowa |
| 60 | John Hoelscher | 42 | Head | Chemistry Professor | Illinois |
| 61 | Ruth Hoelscher | 43 | Wife | — | New Hampshire |
| 62 | Jack Hoelscher | 14 | Son | — | Iowa |
| 63 | Riley Hoelscher | 12 | Son | — | Iowa |
| 64 | John Clark | 33 | Head | Operating Dispatcher | Ohio |
| 65 | Lois Clark | 31 | Wife | — | Iowa |
| 66 | Nancy Clark | 10 | Daughter | — | Iowa |
| 67 | Margery Clark | 4 | Daughter | — | Iowa |
| 68 | Mary Clark | 4 | Daughter | — | Iowa |
| 69 | Frank Engard | 64 | Head | — | Ohio |
| 70 | Matilda Engard | 66 | Wife | — | Illinois |
| 71 | Beulah Engard | 38 | Daughter | Check Room Girl | Illinois |
| 72 | Frances Engard | 37 | Daughter | Switch-Board Operator | Illinois |
| 73 | Mason Engard | 32 | Son | Soft Water Service | Illinois |
| 74 | Michael J. Nace | 57 | Head | Real Estate Agent | Illinois |
| 75 | Zola E. Nace | 56 | Wife | — | Iowa |
| 76 | Evelyn Nace | 20 | Daughter | Stenographer | Minnesota |
| 77 | Katherine Nace | 26 | Daughter | — | Iowa |
| 78 | Joseph Shebeck | 47 | Head | Bookbinder | Iowa |
| 79 | Stella Shebeck | 47 | Wife | — | Iowa |
| 80 | Edward Shebeck | 24 | Son | Orderly | Iowa |
Related Census Records
Pedigree Summary
John
Gen 1 · 2 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)