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John Mahoney — 1940 US Census Record
Model Tree available1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this John Mahoney across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed), with identified parents Patrick & Catherine — first a son (b.~1910), then head of a 4-person household.
Age 30
b. ~1910
Male
Son
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Mahoney |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 30 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Occupation | Checker |
| Industry | Packing House |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 266 |
| Highest Grade | Hs 2 |
| 1935 Residence | Same House |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Occupation | Checker |
| Township / Ward | Chicago |
| Est. Birth Year | ~1910 |
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 |
|---|---|---|---|---|
| Patrick Mahoney | Head | — | 76 | ~1864 |
| Michael Farrici | Other | — | 37 | ~1903 |
| John Mahoney | Son | — | 30 | ~1910 |
| Catherine Mahoney | Spouse | — | 67 | ~1873 |
Census Appearances
1920
Cook, Illinois
Son, age 9
Cook, Illinois · implied b. ~1911 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Mahoney |
| Given Name | John P. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 9 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Canada |
| Mother's Birthplace | New York |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1930
Cook, Illinois
Son, age 19
Cook, Illinois · implied b. ~1911 — 8 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Mahoney |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 19 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Canada |
| Mother's Birthplace | New York |
| Occupation | Clerk |
| Industry | Office |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Son, age 30
Cook-County, Illinois · implied b. ~1910 — 4 household members
| Surname | Mahoney |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 30 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Occupation | Checker |
| Industry | Packing House |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 266 |
| Highest Grade | Hs 2 |
| 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 Mahoney across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Patrick Mahoney (~0.92 confidence) and mother Catherine Mahoney (~0.92 confidence) and mother Rose Mahoney (~0.92 confidence). The pedigree spans 1 generation with 3 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Patrick Mahoney
b. ~1864
Source father
● Household
· direct · ~0.92
Mother
Catherine Mahoney
b. ~1873
Source mother
● Household
· direct · ~0.92
Mother
Rose Mahoney
b. ~1873
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Mahoney
Son · 1940 · age 30 · b. ~1910 · 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-t0627-00957-00203)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Ann Wagner | 22 | Daughter | — | Illinois |
| 2 | Carol Sue Wagner | 1 | Granddaughter | — | Illinois |
| 3 | Harry Ernst | 54 | Head | Psychopedist | Illinois |
| 4 | Martha Ernst | 45 | Wife | Matron | Illinois |
| 5 | Conrad Ernst | 18 | Son | Pin Setter | Indiana |
| 6 | Edward A. Healer | 50 | Head | Credit Man | Illinois |
| 7 | Ellen G. Healer | 52 | Wife | — | Illinois |
| 8 | Warren E. Healer | 16 | Son | — | Illinois |
| 9 | Richard Shinners | 39 | Head | Policeman | Irish Free State |
| 10 | Elizabeth Shinners | 38 | Wife | — | Irish Free State |
| 11 | Mary F. Shinners | 13 | Daughter | — | Illinois |
| 12 | Theresa Shinners | 12 | Daughter | — | Illinois |
| 13 | Betty Ann Shinners | 6 | Daughter | — | Illinois |
| 14 | Richard Shinners | 4 | Son | — | Illinois |
| 15 | Katherine Sullivan | 45 | Head | Bus Attendant | Illinois |
| 16 | Daniel Sullivan | 27 | Son | Office Clerk | Illinois |
| 17 | James Sullivan | 24 | Son | Chauffeur | Illinois |
| 18 | William Miller | 47 | Brother | Plumber | Illinois |
| 19 | Jessie Miller | 42 | Sister | — | Illinois |
| 20 | Mary Lou Miller | 13 | Neice | — | Illinois |
| 21 | Isabel Miller | 7 | Neice | — | Illinois |
| 22 | Alvin Bergsen | 53 | Head | Foreman | Iowa |
| 23 | Lillian Bergsen | 59 | Wife | — | England |
| 24 | Arthur Haines | 31 | Son | — | Illinois |
| 25 | Eleanor Haines | 29 | Daughter | Billing | Illinois |
| 26 | Patrick Mahoney | 76 | Head | — | Irish Free State |
| 27 | Catherine Mahoney | 67 | Wife | — | Irish Free State |
| 28 | John Mahoney THIS PERSON | 30 | Son | Checker | Illinois |
| 29 | Michael Farrici | 37 | Roomer | Barber | Illinois |
| 30 | Edmund Selvage | 43 | Head | Switchman | Illinois |
| 31 | Ida Selvage | 41 | Wife | — | Illinois |
| 32 | Robert Selvage | 18 | Son | — | Illinois |
| 33 | Ernest Schroeder | 70 | Father-in-law | Painter | Illinois |
| 34 | Louise Schroeder | 65 | Mother-in-law | — | Illinois |
| 35 | Joseph Sipple | 47 | Head | Roller | W. Virginia |
| 36 | Mary E. Sipple | 47 | Wife | — | Indiana |
| 37 | John Sipple | 21 | Son | Hot Bed Steel Mill Wkr | Indiana |
| 38 | George Sipple | 20 | Son | Wrapper | Indiana |
| 39 | Margaret Ballantine | 31 | Head | Stenographer | North Dakota |
| 40 | Janet Ballantine | 30 | Sister | Stenographer | North Dakota |
Pedigree Summary
John
Gen 1 · 3 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)