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 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a spouse (b.~1897), then head of a 10-person household.
Age 43
b. ~1897
Female
Spouse
Born: Free State 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 | 43 |
| Marital Status | Married |
| Birthplace | Free State Ireland |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Naturalization Status | Naturalized |
| Additional Details | |
| Industry | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birthplace (normalized) | free state ireland |
| Township / Ward | Chicago |
| Est. Birth Year | ~1897 |
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.
10 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Mary Cahill | Daughter | — | 22 | ~1918 |
| Rita Cahill | Daughter | — | 19 | ~1921 |
| Teresa Cahill | Daughter | — | 5 | ~1935 |
| Thomas Cahill | Son | — | 16 | ~1924 |
| Robert Cahill | Son | — | 7 | ~1933 |
| Francis Cahill | Son | — | 11 | ~1929 |
| Mary Cahill | Spouse | — | 43 | ~1897 |
| John Cahill | Son | — | 18 | ~1922 |
| James Cahill | Head | — | 51 | ~1889 |
| James Cahill | Son | — | 13 | ~1927 |
Census Appearances
1930
Cook, Illinois
Other, age 32
Cook, Illinois · implied b. ~1898 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Cahill |
| Given Name | Mary |
| Relationship to Head | Wife-H |
| Sex | F |
| Color / Race | White |
| Age | 32 |
| Marital Status | Married |
| Birthplace | Free State Ireland |
| Age at First Marriage | 22 |
| Father's Birthplace | Free State Ireland |
| Mother's Birthplace | Free State Ireland |
| Occupation | 1912 |
| Class of Worker | Yes |
| Can Read/Write | Yes |
| Mother Tongue | English |
| Birthplace (normalized) | free state ireland |
1940
Cook-County, Illinois
Spouse, age 43
Cook-County, Illinois · implied b. ~1897 — 10 household members
| Surname | Cahill |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 43 |
| Marital Status | Married |
| Birthplace | Free State Ireland |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Naturalization Status | Naturalized |
| Industry | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birthplace (normalized) | free state 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 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Cahill
Spouse · 1940 · age 43 · b. ~1897 · 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 — 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-t0627-01003-00479)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | John Ludford | 9 | Son | — | Illinois |
| 2 | Robert Ludford | 84 | Father | — | England |
| 3 | Adolph Wilkin | 43 | Head | Auto Mechanic | Missouri |
| 4 | Augusta Wilkin | 44 | Wife | — | Illinois |
| 5 | Charlotte Wilkin | 8 | Daughter | — | Illinois |
| 6 | Ben Pinkowski | 45 | Head | Salesman | Illinois |
| 7 | Elizabeth Pinkowski | 39 | Wife | — | Illinois |
| 8 | Leonard Pinkowski | 13 | Son | — | Wisconsin |
| 9 | Stanley Biedermann | 40 | Brother-in-law | Automobile Mechanic | Illinois |
| 10 | Walter Hoppe | 42 | Head | Bookkeeper | Illinois |
| 11 | Lorraine Hoppe | 43 | Wife | — | Illinois |
| 12 | Audrey Hoppe | 9 | Daughter | — | Illinois |
| 13 | Peter Kachowicz | 34 | Head | Plumber | Illinois |
| 14 | Olga Kachowicz | 36 | Wife | — | New York |
| 15 | Jacob Kachowicz | 11 | Son | — | Illinois |
| 16 | Mary Ann Kachowicz | 10 | Daughter | — | Illinois |
| 17 | James Cahill | 51 | Head | Laborer | Ireland |
| 18 | Mary Cahill THIS PERSON | 43 | Wife | — | Free State Ireland |
| 19 | Mary L. Cahill | 22 | Daughter | Inspector | Illinois |
| 20 | Rita Cahill | 19 | Daughter | Wrapper | Illinois |
| 21 | John Cahill | 18 | Son | Attendant | Illinois |
| 22 | Thomas Cahill | 16 | Son | New Worker | Illinois |
| 23 | James Cahill | 13 | Son | — | Illinois |
| 24 | Francis Cahill | 11 | Son | — | Illinois |
| 25 | Robert Cahill | 7 | Son | — | Illinois |
| 26 | Teresa Cahill | 5 | Daughter | — | Illinois |
| 27 | Harold T. Kurly | 45 | Head | Salesman | Illinois |
| 28 | Lucile Kurly | 41 | Wife | — | Illinois |
| 29 | Thomas Flahive | 35 | Head | Shipping Clerk | Illinois |
| 30 | Alma Flahive | 33 | Wife | — | Wisconsin |
| 31 | Irving Giles | 32 | Head | Manager | Illinois |
| 32 | Beryl Giles | 26 | Wife | — | Illinois |
| 33 | Marjorie Giles | 3 | Daughter | — | Illinois |
| 34 | Janet Giles | 1 | Daughter | — | Illinois |
| 35 | Otto Andrel | 49 | Head | Meter Reader | Illinois |
| 36 | Martha Andrel | 49 | Wife | — | Germany |
| 37 | Eleonore Andrel | 25 | Daughter | Credit Clerk | Illinois |
| 38 | Otto Jr. Andrel | 9 | Son | — | Illinois |
| 39 | Helge Harvey | 56 | Head | Carpenter | Norway |
| 40 | Marie Harvey | 55 | Wife | — | Norway |
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)