MJ
Mary Johnston — 1940 US Census Record
Model Tree available1940 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), with identified parents Mary — first a daughter (b.~1892), then head of a 3-person household.
Age 48
b. ~1892
Female
Daughter
Born: Scotland
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Johnston |
| Given Name | Mary H. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 48 |
| Marital Status | Single |
| Birthplace | Scotland |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Naturalization Status | Naturalized |
| Additional Details | |
| Occupation | Bank Clerk |
| Industry | Savings Bank |
| Class of Worker | PW |
| Hours Worked | 44 |
| Income (1939) | 1100 |
| Highest Grade | 8 |
| 1935 Residence | Same house |
| Birth Country | Scotland |
| Birthplace (normalized) | scotland |
| Occupation | Bank Clerk |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1892 |
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 |
|---|---|---|---|---|
| Margaret Johnston | Daughter | — | 43 | ~1897 |
| Mary Johnston | Daughter | — | 48 | ~1892 |
| Mary Johnston | Head | — | 74 | ~1866 |
Census Appearances
1920
Cook, Illinois
Daughter, age 29
Cook, Illinois · implied b. ~1891 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Johnston |
| Given Name | Margaret |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 29 |
| Marital Status | Single |
| Birthplace | Scotland |
| Year of Immigration | 1910 |
| Naturalization Status | Alien |
| 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 |
Daughter, age 40
Cook, Illinois · implied b. ~1890 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Johnston |
| Given Name | Margaret |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 40 |
| Marital Status | Single |
| Birthplace | Scotland |
| Naturalization Status | Alien |
| Year of Immigration | 1910 |
| 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
Daughter, age 48
Cook-County, Illinois · implied b. ~1892 — 3 household members
| Surname | Johnston |
| Given Name | Mary H. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 48 |
| Marital Status | Single |
| Birthplace | Scotland |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Naturalization Status | Naturalized |
| Occupation | Bank Clerk |
| Industry | Savings Bank |
| Class of Worker | PW |
| Hours Worked | 44 |
| Income (1939) | 1100 |
| Highest Grade | 8 |
| 1935 Residence | Same house |
| 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. Identified parents: mother Mary Johnston (~0.92 confidence). The pedigree spans 1 generation with 1 identified ancestor.
Show:
Gen 1
Parents
confidence ≈ 0.92
Mother
Mary Johnston
b. ~1861
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Mary Johnston
Daughter · 1940 · age 48 · b. ~1892 · Illinois
★ You are viewing this record
Sibling
Margaret Johnston
Sibling · 1940 · age 43
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-t0627-00936-00166)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Charles Wagner | 35 | Son-in-law | Supervisor | New York |
| 2 | Eunice Wagner | 28 | Daughter | — | Illinois |
| 3 | Herbert Meyer | 30 | Head | Tavern Keeper | Illinois |
| 4 | Meta Meyer | 27 | Wife | — | Illinois |
| 5 | Sonya Meyer | 5 | Daughter | — | Illinois |
| 6 | Barbara Meyer | 3 | Daughter | — | Illinois |
| 7 | Lawrence Meyer | 12 | Brother | — | Illinois |
| 8 | Edwin Meyer | 21 | Brother | Bartender | Illinois |
| 9 | John W. Mueller | 50 | Head | Butcher | Illinois |
| 10 | Margaret Mueller | 52 | Wife | — | Pennsylvania |
| 11 | Robert D. Mueller | 21 | Son | Office Clerk | Illinois |
| 12 | Ottie Watta | 54 | Sister | — | Pennsylvania |
| 13 | Martin H. Wright | 49 | Head | Manager | Ohio |
| 14 | Harriett Wright | 44 | Wife | — | Michigan |
| 15 | Harriett Ann Wright | 8 | Daughter | — | Illinois |
| 16 | Irene Olson | 44 | Head | Stenographer | Illinois |
| 17 | Marie Olson | 79 | Mother | — | Sweden |
| 18 | Mary Johnston | 74 | Head | — | Scotland |
| 19 | Mary H. Johnston THIS PERSON | 48 | Daughter | Bank Clerk | Scotland |
| 20 | Margaret Johnston | 43 | Daughter | — | Scotland |
| 21 | Harold K. White | 40 | Head | Salesman | Illinois |
| 22 | Elizabeth White | 41 | Wife | — | Illinois |
| 23 | Harold K. Jr. White | 9 | Son | — | Illinois |
| 24 | Herb Chase | 46 | Head | Window Trimmer | New York |
| 25 | Margaret Chase | 45 | Wife | — | Pennsylvania |
| 26 | John Chase | 21 | Son | Floor Inspector | Illinois |
| 27 | Phillip Chase | 16 | Son | — | Illinois |
| 28 | Maud K. Smith | 64 | Head | — | Ohio |
| 29 | Howard Smith | 39 | Son | Master | Illinois |
| 30 | James H. Smith | 36 | Son | Principal | Illinois |
| 31 | Peter M. Nelson | 44 | Head | Clerk | Illinois |
| 32 | Vernona Nelson | 44 | Wife | — | Illinois |
| 33 | Laverne Nelson | 22 | Daughter | Typist | Illinois |
| 34 | Mark Thomson | 41 | Head | Superintendent | Iowa |
| 35 | Inez Thomson | 38 | Wife | — | Iowa |
| 36 | Michael J. Morrissey | 51 | Head | Mechanic | Illinois |
| 37 | Agnes J. Morrissey | 40 | Wife | Saleslady | Illinois |
| 38 | Robert K. Morrissey | 18 | Son | — | Illinois |
| 39 | Howard E. Morrissey | 12 | Son | — | Illinois |
| 40 | Anna L. Herges | 79 | Mother-in-law | — | Germany |
Related Census Records
Pedigree Summary
Mary + 1 sibling
Gen 1 · 1 parents
~0.92
Max depth 4 (1900–1950 window)
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)