MC
Mary Cahill — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Mary Cahill across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a spouse (b.~1890), then head of a 4-person household.
Age 50
b. ~1890
Female
Spouse
Born: Ireland
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Cahill |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 50 |
| Marital Status | Married |
| Birthplace | Ireland |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Naturalization Status | Naturalized |
| Additional Details | |
| Highest Grade | No 8 |
| 1935 Residence | Same House |
| Birth Country | Ireland |
| Birthplace (normalized) | ireland |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1890 |
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 Mary | Age | Birth yr |
|---|---|---|---|---|
| Daniel Cahill | Son | — | 11 | ~1929 |
| Ellen Cahill | Daughter | — | 25 | ~1915 |
| Mary Cahill | Spouse | — | 50 | ~1890 |
| William Cahill | Head | — | 56 | ~1884 |
Census Appearances
1920
Cook, Illinois
Spouse, age 31
Cook, Illinois · implied b. ~1889 — 2 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Cahill |
| Given Name | Marie |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 31 |
| Marital Status | Married |
| Birthplace | Ireland |
| Year of Immigration | 1908 |
| Naturalization Status | Naturalized |
| Father's Birthplace | Ireland |
| Mother's Birthplace | Ireland |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | English |
| Birth Country | Ireland |
| Birthplace (normalized) | ireland |
1930
Cook, Illinois
Spouse, age 43
Cook, Illinois · implied b. ~1887 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Cahill |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 43 |
| Marital Status | Married |
| Birthplace | Ireland |
| Naturalization Status | Naturalized |
| Year of Immigration | 1909 |
| Age at First Marriage | 27 |
| Father's Birthplace | Ireland |
| Mother's Birthplace | Ireland |
| Can Read/Write | Yes |
| Mother Tongue | English |
| Birth Country | Ireland |
| Birthplace (normalized) | ireland |
1940
Cook-County, Illinois
Spouse, age 50
Cook-County, Illinois · implied b. ~1890 — 4 household members
| Surname | Cahill |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 50 |
| Marital Status | Married |
| Birthplace | Ireland |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Naturalization Status | Naturalized |
| Highest Grade | No 8 |
| 1935 Residence | Same House |
| Birth Country | Ireland |
| Birthplace (normalized) | ireland |
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 Mary Cahill across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
Mary Cahill
Spouse · 1940 · age 50 · b. ~1890 · 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-t0627-00938-00744)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Hugh Jr Ferguson | 7 | Son | — | Illinois |
| 2 | Donald Ferguson | 5 | Son | — | Illinois |
| 3 | John Anderson | 50 | Head | Credit Manager | Michigan |
| 4 | Mabel E Anderson | 49 | Wife | — | Nebraska |
| 5 | Georgia E Anderson | 17 | Daughter | — | Illinois |
| 6 | Harry E White | 46 | Head | Salesman | Illinois |
| 7 | Lucille D White | 34 | Wife | — | Illinois |
| 8 | Richard White | 10 | Son | — | Illinois |
| 9 | Howard White | 12 | Son | — | Illinois |
| 10 | Michael Zeho | 59 | Head | Finisher | Yugo Slavia |
| 11 | Lena Zeho | 44 | Wife | — | Yugo Slavia |
| 12 | John Zeho | 29 | Son | Finisher | Colorado |
| 13 | George Russler | 40 | Head | Salesman | Illinois |
| 14 | Ruth Russler | 40 | Wife | Clerk | Illinois |
| 15 | Colletta Russler | 7 | Daughter | — | Illinois |
| 16 | Helen Moore | 40 | Housekeeper | Housekeeper | Illinois |
| 17 | William Hogan | 58 | Head | Carpenter | Scotland |
| 18 | Marguerite Hogan | 48 | Wife | — | Illinois |
| 19 | Betty Hogan | 23 | Daughter | Stenographer | Indiana |
| 20 | Jane Hogan | 18 | Daughter | New Worker | Indiana |
| 21 | Delphine Hogan | 15 | Daughter | — | Indiana |
| 22 | William H Alderson | 45 | Head | Salesman | Pennsylvania |
| 23 | Julia K Alderson | 44 | Wife | — | Pennsylvania |
| 24 | William Jr Alderson | 18 | Son | New Worker | Pennsylvania |
| 25 | Beverly Alderson | 16 | Daughter | — | Pennsylvania |
| 26 | Mary Alderson | 10 | Daughter | — | Illinois |
| 27 | William Cahill | 56 | Head | Patrolman | Ireland |
| 28 | Mary Cahill THIS PERSON | 50 | Wife | — | Ireland |
| 29 | Ellen Cahill | 25 | Daughter | — | Illinois |
| 30 | Daniel Cahill | 11 | Son | — | Illinois |
| 31 | Joseph Dempsey | 32 | Head | Caulker | Illinois |
| 32 | Anne Dempsey | 30 | Wife | — | Illinois |
| 33 | Jo Anne Dempsey | 3 | Daughter | — | Illinois |
| 34 | Clare Dempsey | 1 | Daughter | — | Illinois |
| 35 | Therese Dempsey | 0 | Daughter | — | Illinois |
| 36 | Sandra Dempsey | 0 | Daughter | — | Illinois |
| 37 | Herman Huhnke | 44 | Head | Stationary Fireman | Illinois |
| 38 | Lena Huhnke | 44 | Wife | — | Illinois |
| 39 | Everett Yount | 30 | Head | Auditor | Illinois |
| 40 | Mary F Yount | 29 | Wife | — | Illinois |
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)