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Mary Mcdonnell — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Mary Mcdonnell across the 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a daughter (b.~1928), then head of a 4-person household.
Age 12
b. ~1928
Female
Daughter
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | McDonnell |
| Given Name | Mary Lou |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Highest Grade | S 6 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1928 |
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 |
|---|---|---|---|---|
| Jack Mcdonnell | Son | — | 14 | ~1926 |
| Malcolm Mcdonnell | Head | — | 39 | ~1901 |
| Mary Mcdonnell | Daughter | — | 12 | ~1928 |
| Rita Mcdonnell | Spouse | — | 40 | ~1900 |
Census Appearances
1930
Cook, Illinois
Daughter, age 2
Cook, Illinois · implied b. ~1928 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McDonald |
| Given Name | Mary Lou |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 2 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Texas |
| Mother's Birthplace | Iowa |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Daughter, age 12
Cook-County, Illinois · implied b. ~1928 — 4 household members
| Surname | McDonnell |
| Given Name | Mary Lou |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Highest Grade | S 6 |
| 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 Mary Mcdonnell across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Mcdonnell
Daughter · 1940 · age 12 · b. ~1928 · Illinois
★ You are viewing this record
Sibling
Jack Mcdonnell
Sibling · 1940 · age 14
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-t0627-01000-00240)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Malcolm Mcdonnell | 39 | Head | Mail Carrier | Texas |
| 2 | Rita D. Mcdonnell | 40 | Wife | — | Iowa |
| 3 | Jack Mcdonnell | 14 | Son | — | Illinois |
| 4 | Mary Lou Mcdonnell THIS PERSON | 12 | Daughter | — | Illinois |
| 5 | Nils Gjostein | 40 | Head | Electrician | Norway |
| 6 | Amelia K. Gjostein | 36 | Wife | — | Norway |
| 7 | Norman Gjostein | 9 | Son | — | Illinois |
| 8 | Edward G. Ecklund | 29 | Head | Pressman | Illinois |
| 9 | Elvira Ecklund | 26 | Wife | — | Illinois |
| 10 | Lois Ecklund | 4 | Daughter | — | Illinois |
| 11 | Joan Ecklund | 1 | Daughter | — | Illinois |
| 12 | Carl D. Shelley | 35 | Head | Inspector | Illinois |
| 13 | Grace Shelley | 34 | Wife | — | Illinois |
| 14 | Grace Shelley | 16 | Daughter | — | Illinois |
| 15 | Marjory Shelley | 12 | Daughter | — | Illinois |
| 16 | Clifford Runion | 27 | Head | Clerk | Illinois |
| 17 | Thelma D. Runion | 24 | Wife | — | Ohio |
| 18 | Ronald Runion | 0 | Son | — | Illinois |
| 19 | Charles M. Ames | 50 | Head | Doctor | Illinois |
| 20 | Marie B. Ames | 45 | Wife | — | Illinois |
| 21 | Mary Keegan | 70 | Head | — | Missouri |
| 22 | Violet Keegan | 33 | Daughter | Stenographer | Missouri |
| 23 | Mary Kelley | 58 | Sister | Housekeeper | Missouri |
| 24 | Claude C. Smith | 34 | Head | Credit Sup. | Indiana |
| 25 | Edna D. Smith | 34 | Wife | — | Indiana |
| 26 | Mary Helen Smith | 10 | Daughter | — | Indiana |
| 27 | Claude C. Jr. Smith | 0 | Son | — | Illinois |
| 28 | Ernest Herzog | 51 | Head | Repairman | Illinois |
| 29 | Anna D. Herzog | 44 | Wife | Operator | Illinois |
| 30 | Doris Herzog | 18 | Daughter | Messenger | Illinois |
| 31 | Clarence G. Garasha | 44 | Head | Teacher | Illinois |
| 32 | Viola H. Garasha | 41 | Wife | — | Illinois |
| 33 | Leonard A. Garasha | 19 | Son | — | Illinois |
| 34 | Anatoly A. Garasha | 15 | Daughter | — | Illinois |
| 35 | Martha D. Krell | 57 | Head | — | Missouri |
| 36 | Joseph Anderlik | 48 | Head | Engineer | Illinois |
| 37 | Mary Rose Anderlik | 39 | Wife | — | Mexico |
| 38 | Jack Anderlik | 17 | Son | — | Illinois |
| 39 | John Anderlik | 14 | Son | — | Illinois |
| 40 | Mary Therese Anderlik | 10 | Daughter | — | 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)