JM
James Mahoney — 1940 US Census Record
Model Tree available1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this James Mahoney across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed), with identified parents Patrick & Daniel — first a son (b.~1915), then head of a 4-person household.
Age 25
b. ~1915
Male
Son
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Mahoney |
| Given Name | James |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Occupation | maintenance man |
| Industry | Hotel |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 1122 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Occupation | Maintenance Man |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1915 |
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 James | Age | Birth yr |
|---|---|---|---|---|
| James Mahoney | Son | — | 25 | ~1915 |
| Lillian Mahoney | Spouse | — | 50 | ~1890 |
| Patrick Mahoney | Head | — | 57 | ~1883 |
| John Mahoney | Son | — | 17 | ~1923 |
Census Appearances
1920
Cook, Illinois
Son, age 4
Cook, Illinois · implied b. ~1916 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Mahoney |
| Given Name | James |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 4 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Illinois |
| Mother's Birthplace | Illinois |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1930
Cook, Illinois
Son, age 14
Cook, Illinois · implied b. ~1916 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Mahoney |
| Given Name | James F |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Illinois |
| Mother's Birthplace | Illinois |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Son, age 25
Cook-County, Illinois · implied b. ~1915 — 4 household members
| Surname | Mahoney |
| Given Name | James |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Occupation | maintenance man |
| Industry | Hotel |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 1122 |
| Highest Grade | Hs 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 James 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 father Daniel Mahoney (~0.92 confidence) and mother Lillian Mahoney (~0.92 confidence). The pedigree spans 1 generation with 3 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Patrick Mahoney
b. ~1881
Source father
● Household
· direct · ~0.92
Father
Daniel Mahoney
b. ~1883
Source father
● Household
· direct · ~0.92
Mother
Lillian Mahoney
b. ~1890
Source mother
● Household
· direct · ~0.92
This person
Anchor record
James Mahoney
Son · 1940 · age 25 · b. ~1915 · Illinois
★ You are viewing this record
Sibling
John Mahoney
Sibling · 1940 · age 17
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-t0627-00938-00236)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Patrick Macmurrough | 68 | Head | Office Clerk | Wisconsin |
| 2 | Theresa Macmurrough | 68 | Wife | — | Wisconsin |
| 3 | Irene Macmurrough | 38 | Daughter | Nurse | Wisconsin |
| 4 | William Spahn | 31 | Head | Organizer | New York |
| 5 | Naomi Spahn | 26 | Wife | — | New York |
| 6 | Harriett Schimmel | 64 | Head | — | Wisconsin |
| 7 | Helen Schimmel | 36 | Daughter | Office Clerk | Wisconsin |
| 8 | Frank Johnson | 43 | Lodger | Shipping Clerk | Maine |
| 9 | Ida Ferriere | 64 | Head | — | Illinois |
| 10 | Genevieve Farwell | 32 | Head | Secretary | Illinois |
| 11 | Edith Farwell | 52 | Mother | — | Illinois |
| 12 | John Ryan | 30 | Head | Owner | Illinois |
| 13 | Loretta Ryan | 30 | Wife | — | Illinois |
| 14 | Arlene Ryan | 2 | Daughter | — | Illinois |
| 15 | John W. Ahern | 50 | Head | Foreman | Illinois |
| 16 | Loraine Ahern | 45 | Wife | — | Illinois |
| 17 | Jack Ahern | 18 | Son | Clerk | Illinois |
| 18 | Louise Keith | 77 | Mother-in-law | — | Iowa |
| 19 | John Moloney | 35 | Head | Policeman | Illinois |
| 20 | Norma Moloney | 34 | Wife | — | Illinois |
| 21 | Patrick J. Malloy | 42 | Head | Conductor | Illinois |
| 22 | Mary Malloy | 30 | Wife | — | Michigan |
| 23 | Bernard W. Malloy | 2 | Son | — | Illinois |
| 24 | Kate Tremont | 40 | Head | — | Illinois |
| 25 | Joseph Tremont | 11 | Son | — | Illinois |
| 26 | Victor Tremont | 8 | Son | — | Illinois |
| 27 | James E. Hogan | 45 | Head | Auditor | Iowa |
| 28 | Jeanette Hogan | 34 | Wife | Bookkeeper | Illinois |
| 29 | Jennie Rodney | 60 | Mother-in-law | — | Illinois |
| 30 | John Patten | 24 | Head | Reservation Salesman | Illinois |
| 31 | Kathryn Patten | 23 | Wife | Secretary | Arkansas |
| 32 | Ella Murray | 70 | Head | — | Illinois |
| 33 | Margaret Murray | 38 | Daughter | — | Illinois |
| 34 | Edward Banks | 37 | Son-in-law | Electrician | Pennsylvania |
| 35 | Anastasia Banks | 33 | Daughter | — | Illinois |
| 36 | Mary B. Banks | 1 | Daughter | — | Illinois |
| 37 | Patrick Mahoney | 57 | Head | Engineer | Illinois |
| 38 | Lillian Mahoney | 50 | Wife | — | Illinois |
| 39 | James Mahoney THIS PERSON | 25 | Son | Maintenance Man | Illinois |
| 40 | John Mahoney | 17 | Son | — | Illinois |
Pedigree Summary
James + 1 sibling
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)