JG
John Griffin — 1940 US Census Record
Model Tree available1940 United States Federal Census · Pocahontas-County, Iowa
Our Model Tree links this John Griffin across the 1920, 1930 and 1940 US Censuses in Pocahontas-County, Iowa (XGBoost, ~Confirmed), with identified parents John & Louise — first a son (b.~1917), then head of a 5-person household.
Age 23
b. ~1917
Male
Son
Born: Iowa
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Pocahontas-County, Iowa |
| Surname | Griffin |
| Given Name | John P. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Varina Town |
| 1935 Residence (County) | Pocahontas |
| Additional Details | |
| Occupation | driver |
| Industry | trucking |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 160 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Occupation | Driver |
| Township / Ward | Varina Town |
| 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.
5 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| George Griffin | Head | — | 47 | ~1893 |
| Lawrence Griffin | Other | — | 18 | ~1922 |
| John Griffin | Son | — | 23 | ~1917 |
| Eugene Griffin | Son | — | 21 | ~1919 |
| Kevin Griffin | Son | — | 19 | ~1921 |
Census Appearances
1920
Pocahontas, Iowa
Son, age 3
Pocahontas, Iowa · implied b. ~1917 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Griffin |
| 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
Pocahontas, Iowa
Son, age 13
Pocahontas, Iowa · implied b. ~1917 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Griffin |
| Given Name | John P |
| 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 |
1940
Pocahontas-County, Iowa
Son, age 23
Pocahontas-County, Iowa · implied b. ~1917 — 5 household members
| Surname | Griffin |
| Given Name | John P. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Varina Town |
| 1935 Residence (County) | Pocahontas |
| Occupation | driver |
| Industry | trucking |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 160 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| 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 Griffin across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father John Griffin (~0.92 confidence) and mother Louise Griffin (~0.92 confidence) and mother Lulu Griffin (~0.92 confidence) and father George Griffin (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
John Griffin
b. ~1892
Source father
● Household
· direct · ~0.92
Mother
Louise Griffin
b. ~1892
Source mother
● Household
· direct · ~0.92
Mother
Lulu Griffin
b. ~1892
Source mother
● Household
· direct · ~0.92
Father
George Griffin
b. ~1893
Source father
● Household
· direct · ~0.92
This person
Anchor record
John Griffin
Son · 1940 · age 23 · b. ~1917 · Iowa
★ You are viewing this record
Sibling
Eugene Griffin
Sibling · 1940 · age 21
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Kevin Griffin
Sibling · 1940 · age 19
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 — Pocahontas-County, Iowa
Open full size
1940 US Federal Census — Pocahontas-County, Iowa
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01191-00229)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Elmer S. Knack | 43 | Head | Employee | Iowa |
| 2 | Esther G. Knack | 39 | Wife | — | Iowa |
| 3 | La Donna L. Knack | 15 | Daughter | — | Iowa |
| 4 | Joseph J. Corey | 48 | Head | Salesman | Iowa |
| 5 | Hazel B. Corey | 45 | Wife | — | Iowa |
| 6 | Genevieve M. Corey | 23 | Daughter | Stenographer | Iowa |
| 7 | Maxine K. Corey | 18 | Daughter | Waitress | Iowa |
| 8 | William J. Corey | 15 | Son | — | Iowa |
| 9 | Marilyn J. Corey | 12 | Daughter | — | Iowa |
| 10 | Ray Welch | 45 | Head | Merchant | Illinois |
| 11 | Agnes M. Welch | 49 | Wife | — | Iowa |
| 12 | Thomas J. Welch | 18 | Son | Clerk | Iowa |
| 13 | Jeanne M. Welch | 17 | Daughter | — | Iowa |
| 14 | Anne M. Welch | 13 | Daughter | — | Iowa |
| 15 | Michael R. Welch | 11 | Son | — | Iowa |
| 16 | Clair R. Welch | 5 | Son | — | Iowa |
| 17 | Martha Streeter | 64 | Sister-in-law | — | Iowa |
| 18 | Ernest Mcdermott | 43 | Head | Trucking | Illinois |
| 19 | Anne L. Mcdermott | 44 | Wife | — | Illinois |
| 20 | Billy Mcdermott | 6 | Son | — | Iowa |
| 21 | Wayne Mayhew | 36 | Head | Teaching | Iowa |
| 22 | Ruth E. Mayhew | 46 | Wife | — | Iowa |
| 23 | Edris V. Mayhew | 9 | Daughter | — | Iowa |
| 24 | Walter E. Vandoren | 64 | Head | Merchant | Michigan |
| 25 | Anna M. Vandoren | 58 | Wife | — | Illinois |
| 26 | Lois M. Vandoren | 16 | Daughter | — | Iowa |
| 27 | George D. Griffin | 47 | Head | — | Iowa |
| 28 | John P. Griffin THIS PERSON | 23 | Son | Driver | Iowa |
| 29 | Eugene B. Griffin | 21 | Son | Driving | Iowa |
| 30 | Kevin J. Griffin | 19 | Son | Labor | Iowa |
| 31 | Lawrence Griffin | 18 | Nephew | Teamster | Iowa |
| 32 | Helen B. B. Fitzgerald | 24 | Head | — | Iowa |
| 33 | Sister M. Melcher | 54 | Head | Teacher | Iowa |
| 34 | Sister M. Bernadette | 56 | Partner | Teacher | Iowa |
| 35 | Sister M. Oligia | 37 | Partner | Teacher | Ireland |
| 36 | Sister M. Florence | 46 | Partner | Teacher | Ireland |
| 37 | Sister M. Benedicta | 45 | Partner | Teacher | Pennsylvania |
| 38 | Sister M. Baptist | 31 | Partner | Teacher | Iowa |
| 39 | Sister M. Raphael | 33 | Partner | Teacher | Iowa |
| 40 | Sister M. Francis Xavier | 28 | Partner | Teacher | Missouri |
Pedigree Summary
John + 2 siblings
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)