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John Blackwell — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Sangamon-County, Illinois
Our Model Tree links this John Blackwell across the 1930 and 1940 US Censuses in Sangamon-County, Illinois (XGBoost, ~Confirmed) — first a head (b.~1906), then head of a 8-person household.
Age 34
b. ~1906
Male
Head
Born: Illinois
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Sangamon-County, Illinois |
| Surname | Blackwell |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | C |
| Age | 34 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Springfield |
| 1935 Residence (County) | Sangamon |
| Additional Details | |
| Occupation | Laborer |
| Industry | WPA Project |
| Class of Worker | GW |
| Hours Worked | 104 |
| Income (1939) | 312 |
| Highest Grade | 8 |
| 1935 Residence | Same house |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Occupation | Laborer |
| Township / Ward | Springfield |
| 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.
8 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Betty Blackwell | Daughter | — | 8 | ~1932 |
| Arthur Blackwell | Son | — | 2 | ~1938 |
| Wordie Blackwell | Daughter | — | ~1940 | |
| Mary Blackwell | Daughter | — | 4 | ~1936 |
| John Blackwell | Son | — | 7 | ~1933 |
| John Blackwell | Head | — | 34 | ~1906 |
| Bessie Blackwell | Spouse | — | 31 | ~1909 |
| Joy Blackwell | Daughter | — | 5 | ~1935 |
Census Appearances
1930
Sangamon, Illinois
Other, age 24
Sangamon, Illinois · implied b. ~1906 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Blackwell |
| Given Name | John Henry |
| Relationship to Head | Brother |
| Sex | M |
| Color / Race | Black |
| Age | 24 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Illinois |
| Mother's Birthplace | Illinois |
| Occupation | Section Lab |
| Industry | Railroad |
| Class of Worker | W |
| Can Read/Write | Yes |
| Veteran | No |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Sangamon-County, Illinois
Head, age 34
Sangamon-County, Illinois · implied b. ~1906 — 8 household members
| Surname | Blackwell |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | C |
| Age | 34 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Springfield |
| 1935 Residence (County) | Sangamon |
| Occupation | Laborer |
| Industry | WPA Project |
| Class of Worker | GW |
| Hours Worked | 104 |
| Income (1939) | 312 |
| Highest Grade | 8 |
| 1935 Residence | Same house |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
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 Blackwell across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
John Blackwell
Head · 1940 · age 34 · b. ~1906 · Illinois
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Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Sangamon-County, Illinois
Open full size
1940 US Federal Census — Sangamon-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00885-00281)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | William Cade | 60 | Head | Laborer | Illinois |
| 2 | Alice Cade | 55 | Wife | — | Missouri |
| 3 | Albert Clarke | 59 | Lodger | Laborer | Illinois |
| 4 | John Graves | 50 | Head | Lineman | Illinois |
| 5 | Ann Graves | 40 | Wife | — | Illinois |
| 6 | Charles Graves | 18 | Son | — | Illinois |
| 7 | Robert Graves | 16 | Son | New Worker | Illinois |
| 8 | James Graves | 14 | Son | — | Illinois |
| 9 | Donald Graves | 11 | Son | — | Illinois |
| 10 | Richard Graves | 3 | Son | — | Illinois |
| 11 | Nelson Graves | 1 | Son | — | Illinois |
| 12 | Thomas Brennan | 38 | Head | Core Maker | Illinois |
| 13 | Mabel Brennan | 38 | Wife | — | Illinois |
| 14 | Esther Brennan | 16 | Daughter | — | Illinois |
| 15 | Charles Brennan | 9 | Son | — | Illinois |
| 16 | Edward Brennan | 4 | Son | — | Illinois |
| 17 | John Blackwell THIS PERSON | 34 | Head | Laborer | Illinois |
| 18 | Bessie Blackwell | 31 | Wife | — | Illinois |
| 19 | Betty Blackwell | 8 | Daughter | — | Illinois |
| 20 | John Blackwell | 7 | Son | — | Illinois |
| 21 | Joy Blackwell | 5 | Daughter | — | Illinois |
| 22 | Mary Blackwell | 4 | Daughter | — | Illinois |
| 23 | Arthur Blackwell | 2 | Son | — | Illinois |
| 24 | Wordie Blackwell | 0 | Daughter | — | Illinois |
| 25 | Herman Oger | 55 | Head | Sell And Repair Shoes | Illinois |
| 26 | Anna Oger | 45 | Wife | — | Missouri |
| 27 | Bertha Oger | 24 | Daughter | — | Illinois |
| 28 | Mary Oger | 17 | Daughter | — | Illinois |
| 29 | Albert Oger | 15 | Son | — | Illinois |
| 30 | Thomas Oger | 11 | Son | — | Illinois |
| 31 | Betty Ann Oger | 7 | Daughter | — | Illinois |
| 32 | William Oger | 4 | Son | — | Illinois |
| 33 | John Oger | 19 | Son | Shoe Repairer | Illinois |
| 34 | Dorothy Oger | 19 | Daughter | — | Illinois |
| 35 | Herman Oger | 0 | Grand-son | — | Illinois |
| 36 | Joseph Smith | 30 | Head | Laborer | Illinois |
| 37 | Millie Smith | 25 | Wife | — | Illinois |
| 38 | Betty Lou Smith | 8 | Daughter | — | Illinois |
| 39 | Elsie Marie Smith | 5 | Daughter | — | Illinois |
| 40 | Robert Louis Smith | 3 | Son | — | Illinois |
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)