MC
Mary Cahill — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Rock-County, Wisconsin
Our Model Tree links this Mary Cahill across the 1930 and 1940 US Censuses in Rock-County, Wisconsin (XGBoost, ~Confirmed) — first a daughter (b.~1912), then head of a 7-person household.
Age 28
b. ~1912
Female
Daughter
Born: Iowa
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Rock-County, Wisconsin |
| Surname | Cahill |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 28 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Janesville |
| 1935 Residence (County) | Rock |
| Additional Details | |
| Occupation | Operator |
| Industry | Telephone |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 242 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same house |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Occupation | Operator |
| Township / Ward | Janesville |
| Est. Birth Year | ~1912 |
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.
7 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Cora Cahill | Spouse | — | 57 | ~1883 |
| John Cahill | Head | — | 58 | ~1882 |
| Genevieve Cahill | Daughter | — | 18 | ~1922 |
| James Cahill | Son | — | 20 | ~1920 |
| Gertrude Cahill | Daughter | — | 25 | ~1915 |
| Joseph Cahill | Son | — | 25 | ~1915 |
| Mary Cahill | Daughter | — | 28 | ~1912 |
Census Appearances
1930
Rock, Wisconsin
Daughter, age 18
Rock, Wisconsin · implied b. ~1912 — 11 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Cahill |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 18 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Can Read/Write | Yes |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Rock-County, Wisconsin
Daughter, age 28
Rock-County, Wisconsin · implied b. ~1912 — 7 household members
| Surname | Cahill |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 28 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Janesville |
| 1935 Residence (County) | Rock |
| Occupation | Operator |
| Industry | Telephone |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 242 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same house |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
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
Daughter · 1940 · age 28 · b. ~1912 · Wisconsin
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Sibling
James Cahill
Sibling · 1940 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Genevieve Cahill
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Cahill
Sibling · 1940 · age 25
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Gertrude Cahill
Sibling · 1940 · age 25
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 — Rock-County, Wisconsin
Open full size
1940 US Federal Census — Rock-County, Wisconsin
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-04520-00351)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Richard Fay | 5 | Son | — | — |
| 2 | Lana G Barrett | 44 | Head | — | Colorado |
| 3 | Thomas Barrett | 18 | Son | — | Iowa |
| 4 | Robert Barrett | 13 | Son | — | Wisconsin |
| 5 | Marie O Bove | 42 | Head | — | Wisconsin |
| 6 | Raymond Bove | 17 | Son | — | Wisconsin |
| 7 | Dorothy Bove | 15 | Daughter | — | Wisconsin |
| 8 | Robert Bove | 11 | Son | — | Wisconsin |
| 9 | Shirley Bove | 10 | Daughter | — | Wisconsin |
| 10 | Eliza Tall | 78 | Head | — | Wisconsin |
| 11 | Etta Hansen | 55 | Lodger | Practical Nurse | Wisconsin |
| 12 | William Morse | 23 | Head | Attendant | Wisconsin |
| 13 | Genevieve Morse | 18 | Wife | — | Wisconsin |
| 14 | Karen Morse | 2 | Daughter | — | Wisconsin |
| 15 | Virgil Sockwell | 28 | Head | Apprentice | Minnesota |
| 16 | Ethel Sockwell | 20 | Wife | Bindery | Wisconsin |
| 17 | Arthur Cherry | 36 | Head | Laborer | New Mexico |
| 18 | Clara Cherry | 31 | Wife | — | Wisconsin |
| 19 | Albert Cherry | 9 | Son | — | Wisconsin |
| 20 | June Cherry | 1 | Daughter | — | Wisconsin |
| 21 | John Cahill | 58 | Head | Baker | Iowa |
| 22 | Cora Cahill | 57 | Wife | — | Iowa |
| 23 | Mary Cahill THIS PERSON | 28 | Daughter | Operator | Iowa |
| 24 | Joseph Cahill | 25 | Son | Laborer | Iowa |
| 25 | Gertrude Cahill | 25 | Daughter | Stenographer | Iowa |
| 26 | James Cahill | 20 | Son | — | Wisconsin |
| 27 | Genevieve Cahill | 18 | Daughter | — | Wisconsin |
| 28 | Albert Gilbertson | 63 | Head | Tool Crib | Wisconsin |
| 29 | Bertha Gilbertson | 65 | Wife | — | Norway |
| 30 | David Cochrane | 54 | Head | Truck Driver | Wisconsin |
| 31 | Laura Cochrane | 51 | Wife | — | Wisconsin |
| 32 | David Cochrane | 20 | Son | Stenographer | Wisconsin |
| 33 | Cecil Burnham | 35 | Head | Fireman | Missouri |
| 34 | Anna Burnham | 33 | Wife | — | Iowa |
| 35 | Raymond Olson | 29 | Head | Yard Foreman | Dakota |
| 36 | Elizabeth Olson | 28 | Wife | — | Wisconsin |
| 37 | Marilyn Olson | 12 | Daughter | — | Wisconsin |
| 38 | Ronald Olson | 11 | Son | — | Wisconsin |
| 39 | William Frischer | 47 | Head | Mechanic | Iowa |
| 40 | Eloie Frischer | 38 | Wife | Produce | Iowa |
Related Census Records
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)