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John Mcelroy — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Madison-County, Illinois
Our Model Tree links this John Mcelroy across the 1930 and 1940 US Censuses in Madison-County, Illinois (XGBoost, ~Confirmed) — first a head (b.~1905), then head of a 8-person household.
Age 35
b. ~1905
Male
Head
Born: Illinois
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Madison-County, Illinois |
| Surname | McElroy |
| Given Name | John |
| Relationship to Head | head |
| Sex | M |
| Color / Race | White |
| Age | 35 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Alton City |
| 1935 Residence (County) | Madison |
| Additional Details | |
| Occupation | Salesman |
| Industry | Hardware Co |
| Class of Worker | PW |
| Hours Worked | 50 |
| Income (1939) | 1150 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Occupation | Salesman |
| Township / Ward | Alton City |
| Est. Birth Year | ~1905 |
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 |
|---|---|---|---|---|
| Adaphia Mcelroy | Daughter | — | 15 | ~1925 |
| Edith Mcelroy | Daughter | — | 3 | ~1937 |
| John Mcelroy | Son | — | 1 | ~1939 |
| Jean Mcelroy | Daughter | — | 7 | ~1933 |
| John Mcelroy | Head | — | 35 | ~1905 |
| Cornelia Mcelroy | Spouse | — | 34 | ~1906 |
| Lucille Mcelroy | Daughter | — | 13 | ~1927 |
| Donald Mcelroy | Son | — | 2 | ~1938 |
Census Appearances
1930
Madison, Illinois
Son, age 25
Madison, Illinois · implied b. ~1905 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McElroy |
| Given Name | John C. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Married |
| Birthplace | Illinois |
| Age at First Marriage | 19 |
| Father's Birthplace | Illinois |
| Mother's Birthplace | Illinois |
| Occupation | Salesman |
| Industry | Insurance |
| Class of Worker | W |
| Can Read/Write | Yes |
| Veteran | No |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Madison-County, Illinois
Head, age 35
Madison-County, Illinois · implied b. ~1905 — 8 household members
| Surname | McElroy |
| Given Name | John |
| Relationship to Head | head |
| Sex | M |
| Color / Race | White |
| Age | 35 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Alton City |
| 1935 Residence (County) | Madison |
| Occupation | Salesman |
| Industry | Hardware Co |
| Class of Worker | PW |
| Hours Worked | 50 |
| Income (1939) | 1150 |
| Highest Grade | No 8 |
| 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 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
John Mcelroy
Head · 1940 · age 35 · b. ~1905 · 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 — Madison-County, Illinois
Open full size
1940 US Federal Census — Madison-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00848-00298)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | John Jr. Gernigin | 42 | head | Foreman | Illinois |
| 2 | Katherine Gernigin | 36 | wife | — | Czech |
| 3 | Mary Gernigin | 16 | daughter | — | Illinois |
| 4 | Virginia Gernigin | 14 | daughter | — | Illinois |
| 5 | Julia Gernigin | 13 | daughter | — | Illinois |
| 6 | John Gernigin | 11 | son | — | Illinois |
| 7 | Homer Gernigin | 9 | son | — | Illinois |
| 8 | John Gernigin | 72 | Father | — | Illinois |
| 9 | Mary Gernigin | 72 | Mother | — | Illinois |
| 10 | John Mcelroy THIS PERSON | 35 | head | Salesman | Illinois |
| 11 | Cornelia Mcelroy | 34 | wife | — | Illinois |
| 12 | Adaphia Mcelroy | 15 | daughter | — | Illinois |
| 13 | Lucille Mcelroy | 13 | daughter | — | Illinois |
| 14 | Jean Mcelroy | 7 | daughter | — | Illinois |
| 15 | Edith Mcelroy | 3 | daughter | — | Illinois |
| 16 | Donald Mcelroy | 2 | son | — | Illinois |
| 17 | John Mcelroy | 1 | son | — | Illinois |
| 18 | Charles Mcelroy | 57 | head | Janitor | Illinois |
| 19 | Trig Mcelroy | 37 | daughter | — | Illinois |
| 20 | Annie Dixon | 70 | head | — | Illinois |
| 21 | Jesse Hudson | 44 | lodger | Clerk | Illinois |
| 22 | Beatrice Bairer | 41 | lodger | — | Canada |
| 23 | Mary Bairer | 5 | lodger | — | Illinois |
| 24 | Claude Ferrell | 41 | head | Time Keeper | Arkansas |
| 25 | Elnora Ferrell | 49 | wife | — | Missouri |
| 26 | Henrietta Herbstreit | 52 | head | — | Illinois |
| 27 | Louise Carran | 26 | daughter | Maid | Illinois |
| 28 | James Carran | 8 | son | — | Illinois |
| 29 | Melba Carran | 4 | daughter | — | Illinois |
| 30 | Arthur Herbstreit | 34 | son | Laborer | Illinois |
| 31 | Paul Herbstreit | 21 | son | Need Worker | Illinois |
| 32 | Milton Herbstreit | 19 | son | Laborer | Illinois |
| 33 | Edward Herbstreit | 17 | son | — | Illinois |
| 34 | Ends Beginning At 408 E 14Th Block | None | — | — | — |
| 35 | — | None | — | — | — |
| 36 | Charles Tok | 42 | head | Brick Layer | Illinois |
| 37 | Wilda Tok | 42 | wife | — | Illinois |
| 38 | Pauline Tok | 19 | daughter | — | Illinois |
| 39 | Lester Means | 49 | head | Clerk | Illinois |
| 40 | Jessie Means | 47 | wife | — | Iowa |
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)