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Joseph Brennan — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Joseph Brennan across the 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a son (b.~1917), then head of a 11-person household.
Age 23
b. ~1917
Male
Son
Born: New York
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Brennan |
| Given Name | Joseph |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | New York |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Occupation | Clerk |
| Industry | Packing Co. |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 1160 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
| Occupation | Clerk |
| Township / Ward | Chicago |
| 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.
11 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Joseph | Age | Birth yr |
|---|---|---|---|---|
| Elizabeth Brennan | Daughter | — | 10 | ~1930 |
| John Brennan | Son | — | 27 | ~1913 |
| Thomas Brennan | Son | — | 26 | ~1914 |
| Joseph Brennan | Son | — | 23 | ~1917 |
| Patricia Brennan | Daughter | — | 9 | ~1931 |
| Timothy Brennan | Head | — | 53 | ~1887 |
| Helen Brennan | Daughter | — | 27 | ~1913 |
| Edward Brennan | Son | — | 16 | ~1924 |
| Thomas Brennan | Other | — | 4 | ~1936 |
| Richard Brennan | Son | — | 20 | ~1920 |
| Mary Brennan | Spouse | — | 52 | ~1888 |
Census Appearances
1930
Cook, Illinois
Son, age 12
Cook, Illinois · implied b. ~1918 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Brennan |
| Given Name | Joseph |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | New York |
| Father's Birthplace | Irish Free State |
| Mother's Birthplace | Northern Ireland |
| Can Read/Write | Yes |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
1940
Cook-County, Illinois
Son, age 23
Cook-County, Illinois · implied b. ~1917 — 11 household members
| Surname | Brennan |
| Given Name | Joseph |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | New York |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Occupation | Clerk |
| Industry | Packing Co. |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 1160 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
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 Joseph Brennan across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Joseph Brennan
Son · 1940 · age 23 · b. ~1917 · Illinois
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Sibling
Thomas Brennan
Sibling · 1940 · age 26
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Patricia Brennan
Sibling · 1940 · age 9
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Richard Brennan
Sibling · 1940 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Helen Brennan
Sibling · 1940 · age 27
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Elizabeth Brennan
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Brennan
Sibling · 1940 · age 27
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Brennan
Sibling · 1940 · age 16
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-t0627-00949-00295)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Edward Hagan | 44 | Head | Truck Driver | Illinois |
| 2 | Mildred Hagan | 51 | Wife | — | Missouri |
| 3 | Frank Makei | 44 | Head | Pattern Cust | Illinois |
| 4 | Helen (A) Makei | 43 | Wife | — | Illinois |
| 5 | Francis Makei | 14 | Son | — | Illinois |
| 6 | Florence Makei | 13 | Daughter | — | Illinois |
| 7 | Robert Makei | 11 | Son | — | Illinois |
| 8 | Lucille Makei | 10 | Daughter | — | Illinois |
| 9 | Florence Makei | 6 | Daughter | — | Illinois |
| 10 | Timothy Brennan | 53 | Head | — | Irish Free State |
| 11 | Mary Brennan | 52 | Wife | — | Northern Ireland |
| 12 | John Brennan | 27 | Son | Clerk | New York |
| 13 | Thomas Brennan | 26 | Son | Salesman | New York |
| 14 | Joseph Brennan THIS PERSON | 23 | Son | Clerk | New York |
| 15 | Richard Brennan | 20 | Son | Clerk | New York |
| 16 | Edward Brennan | 16 | Son | — | New York |
| 17 | Elizabeth Brennan | 10 | Daughter | — | Illinois |
| 18 | Patricia Brennan | 9 | Daughter | — | Illinois |
| 19 | Helen Brennan | 27 | Daughter | — | Illinois |
| 20 | Thomas Brennan | 4 | Grandson | — | Illinois |
| 21 | James Hessings | 38 | Head | Die Maker | Pennsylvania |
| 22 | Marie Hessings | 37 | Wife | — | Illinois |
| 23 | Floyd Hessings | 37 | Brother | Window Trimmer | Pennsylvania |
| 24 | Irene Neville | 37 | Head | — | Illinois |
| 25 | Lorraine Neville | 13 | Daughter | — | Illinois |
| 26 | Jack Neville | 11 | Son | — | Illinois |
| 27 | Irene Neville | 10 | Daughter | — | Illinois |
| 28 | Lawrence Neville | 4 | Son | — | Illinois |
| 29 | James Walsh | 58 | Head | Laborer | Irish Free State |
| 30 | Bridie Walsh | 57 | Wife | — | Irish Free State |
| 31 | Michael Walsh | 35 | Son | Laborer | Irish Free State |
| 32 | Eleanor Walsh | 24 | Daughter | Laborer | Irish Free State |
| 33 | Margaret Walsh | 16 | Daughter | — | Irish Free State |
| 34 | John Collins | 45 | Head | Deputy Clerk | Illinois |
| 35 | Marie Collins | 39 | Wife | — | Illinois |
| 36 | Jack Collins | 16 | Son | — | Illinois |
| 37 | Michael Doyle | 28 | Head | Milk Man | Northern Ireland |
| 38 | Anna Doyle | 30 | Wife | — | Irish Free State |
| 39 | John Doyle | 7 | Son | — | Illinois |
| 40 | James Doyle | 4 | Son | — | Illinois |
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)