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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 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a head (b.~1875), then head of a 4-person household.
Age 65
b. ~1875
Male
Head
Born: Illinois
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | McElroy |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 65 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago city |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Class of Worker | 0 |
| Highest Grade | H 4 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1875 |
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.
4 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Kate Mcelroy | Daughter | — | 22 | ~1918 |
| Mary Mcelroy | Spouse | — | 62 | ~1878 |
| Elizabeth Thiel | Other | — | 52 | ~1888 |
| John Mcelroy | Head | — | 65 | ~1875 |
Census Appearances
1920
Cook, Illinois
Head, age 45
Cook, Illinois · implied b. ~1875 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McElroy |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 45 |
| Marital Status | Married |
| Birthplace | Illinois |
| Father's Birthplace | Illinois |
| Mother's Birthplace | Illinois |
| Occupation | Painter |
| Industry | Shop |
| Class of Worker | W |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | English |
| Home Owned/Rented | O |
| Home Free/Mortgaged | M |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1930
Cook, Illinois
Head, age 55
Cook, Illinois · implied b. ~1875 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McElroy |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 55 |
| Marital Status | Married |
| Birthplace | Illinois |
| Age at First Marriage | 21 |
| Father's Birthplace | Northern Ireland |
| Mother's Birthplace | Northern Ireland |
| Occupation | Painter |
| Industry | Building Contractor |
| Class of Worker | W |
| Can Read/Write | Yes |
| Home Owned/Rented | O |
| Home Value / Rent | 7000 |
| Radio Set | R |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Head, age 65
Cook-County, Illinois · implied b. ~1875 — 4 household members
| Surname | McElroy |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 65 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago city |
| 1935 Residence (County) | Cook |
| Class of Worker | 0 |
| Highest Grade | H 4 |
| 1935 Residence | Same place |
| 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 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
John Mcelroy
Head · 1940 · age 65 · b. ~1875 · Illinois
★ 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 — 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-t0627-00938-00830)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Don Norman | 5 | Son | — | Illinois |
| 2 | Norman Olson | 30 | Brother | Maintenance | Canada |
| 3 | Sara Olson | 84 | Wife | Teacher | Tennessee |
| 4 | Winifred Williams | 76 | Head | — | Vermont |
| 5 | Margaret Williams | 45 | Daughter | Comptometer | Illinois |
| 6 | William Williams | 37 | Son | Flagman | Illinois |
| 7 | Ralph Murphy | 45 | Head | Salesman | Illinois |
| 8 | Ann Murphy | 43 | Wife | — | Illinois |
| 9 | Ralph Jr. Murphy | 3 | Son | — | New York |
| 10 | Alice Mcnuff | 37 | Daughter | School Teacher | Illinois |
| 11 | Alice Mcnuff | 105 | Mother | — | Illinois |
| 12 | Margaret Mcnuff | 85 | Daughter | — | Illinois |
| 13 | Mary Mcnuff | 55 | Daughter | — | Illinois |
| 14 | John Mcelroy THIS PERSON | 65 | Head | — | Illinois |
| 15 | Mary Mcelroy | 62 | Wife | Housework | Illinois |
| 16 | Kate Mcelroy | 22 | Daughter | Sales Clerk | Illinois |
| 17 | Elizabeth Thiel | 52 | Sister in law | Milliner | Illinois |
| 18 | William Roetzheim | 53 | Head | Building Inspector | Illinois |
| 19 | Margaret Roetzheim | 47 | Wife | — | Illinois |
| 20 | Helen Roetzheim | 15 | Daughter | — | Illinois |
| 21 | William H. Roetzheim | 11 | Son | — | Illinois |
| 22 | Lewis Ponchay | 24 | Head | Inspector | Illinois |
| 23 | Elaine Ponchay | 21 | Wife | — | Illinois |
| 24 | Jay Skinner | 32 | Head | Manager | Illinois |
| 25 | Irene Skinner | 32 | Wife | — | Illinois |
| 26 | Ronald Skinner | 6 | Son | — | Illinois |
| 27 | Celine Skinner | 2 | Daughter | — | Illinois |
| 28 | William Dougherty | 40 | Head | Police Officer | Illinois |
| 29 | Dorothy Dougherty | 37 | Wife | — | Illinois |
| 30 | Walter Brown | 57 | Head | Engineer | Canada |
| 31 | Catharine Brown | 59 | Wife | — | Canada |
| 32 | Walter Dorocke | 28 | Head | Laborer | Illinois |
| 33 | Effie Dorocke | 24 | Wife | Packer | Illinois |
| 34 | Peter Brugdis | 53 | Head | Carpenter | Poland |
| 35 | Mary Brugdis | 45 | Wife | — | Poland |
| 36 | Steve Brugdis | 24 | Son | Laborer | Illinois |
| 37 | Pearl Brugdis | 22 | Daughter | Bookkeeper | Illinois |
| 38 | Theodore Brugdis | 20 | Son | Truck Driver | Illinois |
| 39 | James Creery | 74 | Head | Inspector | Eire |
| 40 | Catherine Creery | 47 | Wife | — | Eire |
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)