MK
Mary Knox — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Mchenry-County, Illinois
Our Model Tree links this Mary Knox across the 1930 and 1940 US Censuses in Mchenry-County, Illinois (XGBoost, ~Confirmed) — first a daughter (b.~1922), then head of a 11-person household.
Age 18
b. ~1922
Female
Daughter
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Mchenry-County, Illinois |
| Surname | Knox |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 18 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Nunda Township |
| 1935 Residence (County) | McHenry |
| Additional Details | |
| Occupation | secret. bookkeeper |
| Industry | wholesale dairy |
| Class of Worker | PW |
| Hours Worked | 32 |
| Income (1939) | 601 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Occupation | Secret. Bookkeeper |
| Township / Ward | Nunda Township |
| Est. Birth Year | ~1922 |
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 Mary | Age | Birth yr |
|---|---|---|---|---|
| John Knox | Son | — | 7 | ~1933 |
| David Knox | Son | — | 1 | ~1939 |
| Robert Knox | Son | — | 13 | ~1927 |
| Mary Knox | Daughter | — | 18 | ~1922 |
| Eunice Knox | Daughter | — | 8 | ~1932 |
| Edna Knox | Spouse | — | 43 | ~1897 |
| Julia Knox | Daughter | — | 12 | ~1928 |
| Helen Knox | Daughter | — | 15 | ~1925 |
| Robert Knox | Head | — | 46 | ~1894 |
| Howard Knox | Son | — | 11 | ~1929 |
| Edward Knox | Son | — | 9 | ~1931 |
Census Appearances
1930
Mchenry, Illinois
Daughter, age 8
Mchenry, Illinois · implied b. ~1922 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Knox |
| Given Name | Mary M. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 8 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Illinois |
| Mother's Birthplace | Illinois |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Mchenry-County, Illinois
Daughter, age 18
Mchenry-County, Illinois · implied b. ~1922 — 11 household members
| Surname | Knox |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 18 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Nunda Township |
| 1935 Residence (County) | McHenry |
| Occupation | secret. bookkeeper |
| Industry | wholesale dairy |
| Class of Worker | PW |
| Hours Worked | 32 |
| Income (1939) | 601 |
| Highest Grade | Hs 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 Knox across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Knox
Daughter · 1940 · age 18 · b. ~1922 · Illinois
★ You are viewing this record
Sibling
John Knox
Sibling · 1940 · age 7
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
David Knox
Sibling · 1940 · age 1
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Robert Knox
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Helen Knox
Sibling · 1940 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Eunice Knox
Sibling · 1940 · age 8
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Knox
Sibling · 1940 · age 9
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Julia Knox
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Howard Knox
Sibling · 1940 · age 11
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 — Mchenry-County, Illinois
Open full size
1940 US Federal Census — Mchenry-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00840-00998)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Robert Knox | 46 | Head | Liquor Warehouse | Illinois |
| 2 | Edna Knox | 43 | Wife | — | Illinois |
| 3 | Mary Knox THIS PERSON | 18 | Daughter | Secret. Bookkeeper | Illinois |
| 4 | Helen Knox | 15 | Daughter | — | Illinois |
| 5 | Robert Jr. Knox | 13 | Son | — | Illinois |
| 6 | Julia Knox | 12 | Daughter | — | Illinois |
| 7 | Howard Knox | 11 | Son | — | Illinois |
| 8 | Edward Knox | 9 | Son | — | Illinois |
| 9 | Eunice Knox | 8 | Daughter | — | Illinois |
| 10 | John Knox | 7 | Son | — | Illinois |
| 11 | David Knox | 1 | Son | — | Illinois |
| 12 | Walter J. Walsh | 59 | Head | Farmer | Illinois |
| 13 | Elizabeth Walsh | 50 | Wife | — | Illinois |
| 14 | John Hoogenboom | 59 | Head | — | Holland |
| 15 | Marie Hoogenboom | 58 | Wife | — | Holland |
| 16 | John Walsh | 75 | Head | — | Illinois |
| 17 | Frank A. B. Holmes | 56 | Head | Tinsmith | Illinois |
| 18 | Lillian Holmes | 52 | Wife | — | Illinois |
| 19 | Frank Jr. Holmes | 25 | Son | Fireman | Illinois |
| 20 | Edwin Sullivan | 63 | Head | Dentist | Canada |
| 21 | Gladys Sullivan | 48 | Wife | — | Canada |
| 22 | Edwin Jr. Sullivan | 21 | Son | Advertising | Illinois |
| 23 | Virginia Sullivan | 18 | Daughter | — | Illinois |
| 24 | Eugene Sullivan | 64 | Head | Linotypist Helper | Canada |
| 25 | Anna Sullivan | 54 | Wife | — | Norway |
| 26 | Hans Soldwisch | 76 | Head | Farmer | Germany |
| 27 | Harry Soldwisch | 48 | Son | — | Illinois |
| 28 | Martin E. Bhenaf|Bhenas | 34 | Head | Farmer | Illinois |
| 29 | Cordella Bhenaf|Bhenas | 30 | Wife | — | Illinois |
| 30 | Agnes Bhenaf|Bhenas | 8 | Daughter | — | Illinois |
| 31 | Patricia Bhenaf|Bhenas | 7 | Daughter | — | Illinois |
| 32 | Martin Jr. Bhenaf|Bhenas | 5 | Son | — | Illinois |
| 33 | Louise Bhenaf|Bhenas | 3 | Daughter | — | Illinois |
| 34 | Joanne Bhenaf|Bhenas | 1 | Daughter | — | Illinois |
| 35 | Eveline R. Larkin | 58 | Head | School Teacher | Poland |
| 36 | George A. Larkin | 25 | Son | Carpenter | Illinois |
| 37 | Margaret M. Larkin | 23 | Daughter | School Teacher | Illinois |
| 38 | Florence E. Larkin | 22 | Daughter | Librarian | Illinois |
| 39 | James L. Larkin | 14 | Son | Bank Clerk | Illinois |
| 40 | Gerald J. Larkin | 16 | 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)