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Mary Byrne — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Mary Byrne across the 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a daughter (b.~1917), then head of a 8-person household.
Age 23
b. ~1917
Female
Daughter
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Byrne |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Class of Worker | H |
| Income (1939) | 0 |
| Highest Grade | H-4 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1917 |
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.
8 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Irene Byrne | Daughter | — | 18 | ~1922 |
| Helen Byrne | Daughter | — | 28 | ~1912 |
| Mary Byrne | Daughter | — | 23 | ~1917 |
| Julia Byrne | Daughter | — | 33 | ~1907 |
| James Byrne | Head | — | 76 | ~1864 |
| John Byrne | Son | — | 34 | ~1906 |
| Donald Byrne | Son | — | 17 | ~1923 |
| Catherine Byrne | Spouse | — | 56 | ~1884 |
Census Appearances
1930
Cook, Illinois
Daughter, age 12
Cook, Illinois · implied b. ~1918 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Byrnes |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Irish Free State |
| Mother's Birthplace | Irish Free State |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Daughter, age 23
Cook-County, Illinois · implied b. ~1917 — 8 household members
| Surname | Byrne |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Class of Worker | H |
| Income (1939) | 0 |
| Highest Grade | H-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 Mary Byrne across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Byrne
Daughter · 1940 · age 23 · b. ~1917 · Illinois
★ You are viewing this record
Sibling
Irene Byrne
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Julia Byrne
Sibling · 1940 · age 33
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Donald Byrne
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Byrne
Sibling · 1940 · age 34
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Helen Byrne
Sibling · 1940 · age 28
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-t0627-00987-00307)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Oscar Van Steensite | 36 | Head | Chrome Polisher | Belgium |
| 2 | Rose Van Steensite | 35 | Wife | — | Illinois |
| 3 | Robert Van Steensite | 13 | Son | — | Illinois |
| 4 | Virginia Van Steensite | 11 | Daughter | — | Illinois |
| 5 | James Byrne | 76 | Head | Laborer | Irish Free State |
| 6 | Catherine Byrne | 56 | Wife | — | Irish Free State |
| 7 | John Byrne | 34 | Son | Sign Painter | Illinois |
| 8 | Julia Byrne | 33 | Daughter | Telephone Operator | Illinois |
| 9 | Helen Byrne | 28 | Daughter | Inserter | Illinois |
| 10 | Mary Byrne THIS PERSON | 23 | Daughter | — | Illinois |
| 11 | Irene Byrne | 18 | Daughter | Stenographer | Illinois |
| 12 | Donald Byrne | 17 | Son | — | Illinois |
| 13 | William Holzer | 53 | Head | Auto Repair Compositor | Austria |
| 14 | Marie Holzer | 49 | Wife | — | Austria |
| 15 | Reginald Holzer | 12 | Son | — | Illinois |
| 16 | Arthur Buzan | 39 | Head | Heat Treater | Missouri |
| 17 | Madge Buzan | 35 | Wife | — | Kentucky |
| 18 | Lois Buzan | 6 | Daughter | — | Illinois |
| 19 | Hattie Forrest | 60 | Head | — | Germany |
| 20 | Jeannette Bender | 30 | Lodger | Physical Education Instructor | Illinois |
| 21 | Ferdinand Kernmuthmuller | 50 | Head | Tanner | Germany |
| 22 | Margaret Kernmuthmuller | 33 | Wife | — | Germany |
| 23 | Margaret Kernmuthmuller | 28 | Daughter | Seamstress | Germany |
| 24 | Alice Kernmuthmuller | 4 | Daughter | — | Illinois |
| 25 | Nephi Kernmuthmuller | 0 | Son | — | Illinois |
| 26 | Charles Kuras | 46 | Head | Laborer | Poland |
| 27 | Victoria Kuras | 48 | Wife | Pantry Worker | Poland |
| 28 | Sophia Kuras | 20 | Daughter | Dictaphone Operator | Illinois |
| 29 | Alexander Kuras | 16 | Son | — | Illinois |
| 30 | Edward Kuras | 14 | Son | — | Illinois |
| 31 | Helen Kuras | 12 | Daughter | — | Illinois |
| 32 | Alice Kuras | 7 | Daughter | — | Illinois |
| 33 | William Gursky | 43 | Head | Machinist | Illinois |
| 34 | Ida Gursky | 42 | Wife | — | Illinois |
| 35 | Herbert Gursky | 22 | Son | Machinist | Illinois |
| 36 | Mildred Gursky | 18 | Daughter | Bakery Clerk | Illinois |
| 37 | William Bastian | 37 | Head | Automotive Service Machinist | Germany |
| 38 | Hilda Bastian | 27 | Wife | — | Germany |
| 39 | Richard Bastian | 6 | Son | — | Illinois |
| 40 | Lester Condon | 50 | Head | — | Wisconsin |
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)