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John Mcelroy — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this John Mcelroy across the 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a son (b.~1927), then head of a 6-person household.
Age 13
b. ~1927
Male
Son
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | McElroy |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Industry | 0 |
| Highest Grade | No 5 |
| 1935 Residence | Same house |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1927 |
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.
6 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Hugh Mcelroy | Head | — | 59 | ~1881 |
| Hugh Mcelroy | Son | — | 15 | ~1925 |
| John Mcelroy | Son | — | 13 | ~1927 |
| Josephine Mcelroy | Spouse | — | 43 | ~1897 |
| Anna Mcelroy | Daughter | — | 18 | ~1922 |
| Edward Mcelroy | Son | — | 17 | ~1923 |
Census Appearances
1930
Cook, Illinois
Son, age 3
Cook, Illinois · implied b. ~1927 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McElroy |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 3 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | New York |
| Mother's Birthplace | Czecho Slovakia |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Son, age 13
Cook-County, Illinois · implied b. ~1927 — 6 household members
| Surname | McElroy |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Industry | 0 |
| Highest Grade | No 5 |
| 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 Mcelroy across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Mcelroy
Son · 1940 · age 13 · b. ~1927 · Illinois
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Sibling
Anna Mcelroy
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Mcelroy
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Hugh Mcelroy
Sibling · 1940 · age 15
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 — Cook-County, Illinois
Open full size
1940 US Federal Census — Cook-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00975-00229)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | John Considine | 35 | Head | Laborer | Irish Free State |
| 2 | Nora Considine | 32 | Wife | — | Irish Free State |
| 3 | Nora A Considine | 9 | Daughter | — | Illinois |
| 4 | James Considine | 8 | Son | — | Illinois |
| 5 | John Considine | 5 | Son | — | Illinois |
| 6 | Martin Considine | 3 | Son | — | Illinois |
| 7 | Joanna Joyce | 69 | Head | — | Illinois |
| 8 | John T Owen | 56 | Head | — | Illinois |
| 9 | Margaret Owen | 51 | Wife | — | Illinois |
| 10 | Hugh Mcelroy | 59 | Head | Elevator Operator | New York |
| 11 | Josephine Mcelroy | 43 | Wife | — | Czechoslovakia |
| 12 | Anna Mcelroy | 18 | Daughter | Press Feeder | Illinois |
| 13 | Edward Mcelroy | 17 | Son | — | Illinois |
| 14 | Hugh Jr Mcelroy | 15 | Son | — | Illinois |
| 15 | John Mcelroy THIS PERSON | 13 | Son | — | Illinois |
| 16 | Ely D Gray | 42 | Head | Willow Furn. Maker | Greece |
| 17 | Sotery Gray | 31 | Wife | Willow Furn. Case Maker | Indiana |
| 18 | Ramon Gomez | 39 | Lodger | — | Mexico |
| 19 | Nicklos Vichouly | 65 | Lodger | — | Greece |
| 20 | Rufugio Ryna | 62 | Lodger | — | Mexico |
| 21 | Stella Gust | 40 | Lodger | — | Ohio |
| 22 | Bank Bragg | 64 | Head | — | Ohio |
| 23 | Matt Bragg | 42 | Son | Laborer | Illinois |
| 24 | Alfred Valero | 24 | Head | Puncher | Mexico |
| 25 | Pomposa Valero | 24 | Wife | — | Mexico |
| 26 | Manuela Valero | 38 | Mother | Presser | Mexico |
| 27 | Angelica Valero | 21 | Sister | Maid | Mexico |
| 28 | Alfonso Valero | 18 | Brother | — | Texas |
| 29 | Carmen Valero | 16 | Sister | — | Texas |
| 30 | Gloria Valero | 14 | Sister | — | Texas |
| 31 | Victor Valero | 7 | Brother | — | Texas |
| 32 | Here Ends Block 22 And Begins Block 23 Valero | None | — | — | — |
| 33 | Lawrence Pfohman | 43 | Head | Fire Urgent | Illinois |
| 34 | Louise Pfohman | 43 | Wife | Waitress | Illinois |
| 35 | Basil Dovalis | 43 | Head | Elevator Operator | Greece |
| 36 | Jennie Dovalis | 42 | Wife | — | Greece |
| 37 | Nickolas Dovalis | 20 | Son | Clerk | Greece |
| 38 | George Dovalis | 10 | Son | — | Illinois |
| 39 | Ernest Dovalis | 8 | Son | — | Illinois |
| 40 | Thomas Hallas | 62 | Head | Shoe Repairer | Greece |
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)