MC
Mary Conley — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Mary Conley across the 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a daughter (b.~1923), then head of a 8-person household.
Age 17
b. ~1923
Female
Daughter
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Conley |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 17 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Additional Details | |
| 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 | ~1923 |
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 |
|---|---|---|---|---|
| Thomas Conley | Son | — | 32 | ~1908 |
| Paul Conley | Son | — | 27 | ~1913 |
| Marcella Conley | Daughter | — | 36 | ~1904 |
| Mary Conley | Daughter | — | 17 | ~1923 |
| Laura Conley | Head | — | 56 | ~1884 |
| Elizabeth Conley | Other | — | 30 | ~1910 |
| Raymond Conley | Son | — | 23 | ~1917 |
| Barbara Conley | Daughter | — | 2 | ~1938 |
Census Appearances
1930
Cook, Illinois
Daughter, age 6
Cook, Illinois · implied b. ~1924 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Coonley |
| Given Name | Mary Jane |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 6 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Illinois |
| Mother's Birthplace | Illinois |
| Occupation | none |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Daughter, age 17
Cook-County, Illinois · implied b. ~1923 — 8 household members
| Surname | Conley |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 17 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| 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 Conley across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Conley
Daughter · 1940 · age 17 · b. ~1923 · Illinois
★ You are viewing this record
Sibling
Marcella Conley
Sibling · 1940 · age 36
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Raymond Conley
Sibling · 1940 · age 23
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Paul Conley
Sibling · 1940 · age 27
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Barbara Conley
Sibling · 1940 · age 2
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Thomas Conley
Sibling · 1940 · age 32
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-t0627-00989-00913)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | George Koppel | 59 | Head | Proprietor | Russia |
| 2 | Anna Koppel | 57 | Wife | — | Russia |
| 3 | Ben Musmelstein | 53 | Head | Proprietor | Hungary |
| 4 | Dora Musmelstein | 44 | Wife | — | Hungary |
| 5 | Hattie Musmelstein | 21 | Son | — | Illinois |
| 6 | Anna Wilson | 35 | Head | Telegrapher | Illinois |
| 7 | Reeder Wilson | 16 | Son | — | Illinois |
| 8 | Louis Wengert | 30 | Head | Lawyer | Illinois |
| 9 | Eleanor Wengert | 25 | Wife | — | Illinois |
| 10 | Willis Farkie | 59 | Head | Traffic Manager | Michigan |
| 11 | Lillian Farkie | 57 | Wife | — | Iowa |
| 12 | George Gatty | 70 | Head | Lawyer | Illinois |
| 13 | Esther Gatty | 60 | Wife | — | Sweden |
| 14 | Alvin Forge | 48 | Head | Laborer | Indiana |
| 15 | Lannie Forge | 43 | Wife | — | Illinois |
| 16 | Evelyn Forge | 20 | Daughter | Stenographer | Illinois |
| 17 | Gladys Forge | 15 | Daughter | — | Illinois |
| 18 | Regina Haas | 77 | Head | — | Norway |
| 19 | Buelah Haas | 31 | Daughter | Conductor | Illinois |
| 20 | Susan Glass | 73 | Head | — | Belgium |
| 21 | John Potts | 70 | Head | — | Poland |
| 22 | Frances Potts | 29 | Daughter | Sewing Machine Operator | Illinois |
| 23 | Helen Potts | 28 | Daughter | Sewing Machine Operator | Illinois |
| 24 | Angela Potts | 24 | Daughter | Trimmer Underwear | Illinois |
| 25 | Arthur Boettger | 66 | Head | — | Illinois |
| 26 | Bessie Boettger | 74 | Sister | — | Germany |
| 27 | Peter Johnson | 49 | Head | Bartender | Norway |
| 28 | Julia Johnson | 47 | Wife | — | Norway |
| 29 | Laura Conley | 56 | Head | — | Illinois |
| 30 | Marcella Conley | 36 | Daughter | Teacher | Illinois |
| 31 | Paul Conley | 27 | Son | Stationer | Illinois |
| 32 | Raymond Conley | 23 | Son | — | Illinois |
| 33 | Mary Conley THIS PERSON | 17 | Daughter | — | Illinois |
| 34 | Thomas Conley | 32 | Son | Lawyer | Illinois |
| 35 | Elizabeth Conley | 30 | Daughter-in-law | — | Illinois |
| 36 | Barbara Conley | 2 | Daughter | — | Illinois |
| 37 | Joseph O'Donnell | 52 | Head | Lawyer | Illinois |
| 38 | Mabel O'Donnell | 47 | Wife | — | Illinois |
| 39 | Joseph O'Donnell | 20 | Son | — | Illinois |
| 40 | Thomas O'Donnell | 18 | Son | — | 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)