MJ
Mary Johnston — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Mary Johnston across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a spouse (b.~1891), then head of a 3-person household.
Age 49
b. ~1891
Female
Spouse
Born: Scotland
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Johnston |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 49 |
| Marital Status | Married |
| Birthplace | Scotland |
| 1935 Residence (City) | Chicago |
| Naturalization Status | Naturalized |
| Additional Details | |
| Occupation | H |
| Industry | 0 |
| Highest Grade | Hs 4 |
| Birth Country | Scotland |
| Birthplace (normalized) | scotland |
| Occupation | H |
| Township / Ward | Chicago |
| Est. Birth Year | ~1891 |
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.
3 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Doris Johnston | Daughter | — | 25 | ~1915 |
| Jack Johnston | Head | — | 50 | ~1890 |
| Mary Johnston | Spouse | — | 49 | ~1891 |
Census Appearances
1920
Cook, Illinois
Spouse, age 27
Cook, Illinois · implied b. ~1893 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Johnston |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 27 |
| Marital Status | Married |
| Birthplace | Scotland |
| Year of Immigration | 1900 |
| Naturalization Status | First papers filed |
| Father's Birthplace | Scotland |
| Mother's Birthplace | Scotland |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | English |
| Birth Country | Scotland |
| Birthplace (normalized) | scotland |
1930
Cook, Illinois
Other, age 38
Cook, Illinois · implied b. ~1892 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Johnston |
| Given Name | Mary |
| Relationship to Head | Wife-H |
| Sex | F |
| Color / Race | White |
| Age | 38 |
| Marital Status | Married |
| Birthplace | Scotland |
| Naturalization Status | Naturalized |
| Year of Immigration | 1901 |
| Age at First Marriage | 20 |
| Father's Birthplace | Scotland |
| Mother's Birthplace | Scotland |
| Can Read/Write | Yes |
| Mother Tongue | English |
| Birth Country | Scotland |
| Birthplace (normalized) | scotland |
1940
Cook-County, Illinois
Spouse, age 49
Cook-County, Illinois · implied b. ~1891 — 3 household members
| Surname | Johnston |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 49 |
| Marital Status | Married |
| Birthplace | Scotland |
| 1935 Residence (City) | Chicago |
| Naturalization Status | Naturalized |
| Occupation | H |
| Industry | 0 |
| Highest Grade | Hs 4 |
| Birth Country | Scotland |
| Birthplace (normalized) | scotland |
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 Johnston across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Johnston
Spouse · 1940 · age 49 · b. ~1891 · Illinois
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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
38 people indexed on this census page (nara:1940:m-t0627-00933-01032)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Katharine Donahue | 53 | Sister | — | Michigan |
| 2 | Paul A Mcgovern | 28 | Head | 24 | Indiana |
| 3 | Bernice Mcgovern | 28 | Wife | — | Indiana |
| 4 | James Mcgovern | 1 | Son | — | — |
| 5 | Horace F Barley | 49 | Head | 42 | Illinois |
| 6 | Amie Barley | 50 | Wife | — | Illinois |
| 7 | Patrick King | 32 | Head | 60 | Irish Free State |
| 8 | Ann King | 33 | Wife | — | Irish Free State |
| 9 | Daniel King | 3 | Son | — | Illinois |
| 10 | William Scally | 30 | Head | 24 | Irish Free State |
| 11 | Harriet A Scally | 30 | Wife | — | Ohio |
| 12 | William Scally | 3 | Son | — | Illinois |
| 13 | John Scally | 1 | Son | — | Illinois |
| 14 | Harry F. Flack | 44 | Head | 65 | Indiana |
| 15 | Mable W Flack | 44 | Wife | H | Indiana |
| 16 | Harry Jr. Flack | 18 | Son | — | Indiana |
| 17 | Betty A Flack | 15 | Daughter | — | Indiana |
| 18 | Gertrude Groppe | 60 | Head | H | Germany |
| 19 | Conrad Groppe | 57 | Brother | — | Illinois |
| 20 | Agnes Groppe | 55 | Sister | H | Illinois |
| 21 | Jack Johnston | 50 | Head | 48 | Scotland |
| 22 | Mary Johnston THIS PERSON | 49 | Wife | H | Scotland |
| 23 | Doris Johnston | 25 | Daughter | 48 | Illinois |
| 24 | Lewis Gordon | 56 | Head | — | Russia |
| 25 | Jennie Gordon | 46 | Wife | — | Indiana |
| 26 | Harry Gordon | 24 | Son | 52 | Illinois |
| 27 | Myron Gordon | 15 | Son | — | Illinois |
| 28 | Ben Miller | 49 | Brother-in-law | 40 | Indiana |
| 29 | Loraine Deegan | 42 | Head | H | New York |
| 30 | Harry J Deegan | 24 | Son | 42 | Illinois |
| 31 | Ellis Deegan | 22 | Son | 40 | Illinois |
| 32 | Charles Deegan | 19 | Son | 39 | Illinois |
| 33 | Donald Deegan | 17 | Son | — | Illinois |
| 34 | Mela Kelly | 54 | Head | 45 | Illinois |
| 35 | Richard Kelly | 22 | Son | 44 | Illinois |
| 36 | Marion Kelly | 22 | Daughter | 45 | Illinois |
| 37 | Louis Jensen | 59 | Head | 48 | Minnesota |
| 38 | Katherine Jensen | 57 | Wife | — | 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)