MO
Mary Olsen — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Mary Olsen across the 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a spouse (b.~1907), then head of a 7-person household.
Age 33
b. ~1907
Female
Spouse
Born: Illinois
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Olsen |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 33 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago - City |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1907 |
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.
7 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| William Olsen | Son | — | 9 | ~1931 |
| Jean Olsen | Daughter | — | 6 | ~1934 |
| Mary Olsen | Spouse | — | 33 | ~1907 |
| Vernon Olsen | Son | — | 14 | ~1926 |
| Vernon Olsen | Head | — | 33 | ~1907 |
| Donald Olsen | Son | — | 12 | ~1928 |
| Robert Whitman | Other | — | 58 | ~1882 |
Census Appearances
1930
Cook, Illinois
Daughter, age 22
Cook, Illinois · implied b. ~1908 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Olson |
| Given Name | Maria |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 22 |
| Marital Status | Married |
| Birthplace | Illinois |
| Age at First Marriage | 19 |
| Father's Birthplace | New York |
| Mother's Birthplace | Norway |
| Occupation | Proof Reader |
| Industry | Law matter |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Spouse, age 33
Cook-County, Illinois · implied b. ~1907 — 7 household members
| Surname | Olsen |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 33 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago - City |
| 1935 Residence (County) | Cook |
| Highest Grade | No 8 |
| 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 Olsen across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Olsen
Spouse · 1940 · age 33 · b. ~1907 · Illinois
★ You are viewing this record
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-t0627-00990-00687)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Robert A. Green | 52 | Lodger | Laborer | Illinois |
| 42 | Henry Sildeberg | 52 | Lodger | Painter | Denmark |
| 43 | Nels P. Pederson | 54 | Lodger | Bartender | Denmark |
| 44 | Lester S. Inwood | 21 | Lodger | Laborer | Illinois |
| 45 | Leo C. Christophersen | 52 | Lodger | Bartender | Denmark |
| 46 | Homer W. Forsberg | 23 | Lodger | Contractor | Illinois |
| 47 | Virginia Forsberg | 21 | Lodger | Factory Worker | Doesn't know |
| 48 | William C. Meyer | 65 | Lodger | Parcel Man | Illinois |
| 49 | Edward Wolf | 50 | Head | Rigger | Norway |
| 50 | Bernice B. Wolf | 22 | Daughter | Candy Wrapper | Illinois |
| 51 | Extra Line Wolf | None | extra line | Extra Line | extra line |
| 52 | Enoch Thorsen | 40 | Head | Electric Welder | Norway |
| 53 | Lynneal B. Thorsen | 36 | Wife | — | Oklahoma |
| 54 | Muriel Haynes | 9 | Stepdaughter | — | Oklahoma |
| 55 | Joseph Green | 33 | Head | Auto Mechanic | Czechoslovakia |
| 56 | Mary Green | 31 | Wife | Speedometer Inspector | Pennsylvania |
| 57 | — | None | — | — | — |
| 58 | Joseph L. Weis | 63 | Head | Medical Doctor | Hungary |
| 59 | Fannie Weis | 60 | Wife | — | Hungary |
| 60 | Erwin B. Dettmer | 51 | Head | Electrician | Illinois |
| 61 | Frances E. Dettmer | 58 | Wife | Laundress | Ohio |
| 62 | Walter S. Dettmer | 27 | Son | Grocery Clerk | Illinois |
| 63 | George H. Dettmer | 23 | Son | Grocery Clerk | Illinois |
| 64 | Dorothy G. Dettmer | 16 | Daughter | — | Illinois |
| 65 | Kenneth D. Dettmer | 14 | Son | — | Illinois |
| 66 | Lorraine M. Dettmer | 9 | Daughter | — | Illinois |
| 67 | Casimir Wolnick | 31 | Head | Tool And Die Maker | Illinois |
| 68 | Adeline B. Wolnick | 30 | Wife | — | Illinois |
| 69 | Donald Wolnick | 10 | Son | — | Illinois |
| 70 | Norman Wolnick | 5 | Son | — | Illinois |
| 71 | Pauline Zahara | 74 | Mother-in-law | — | Poland |
| 72 | Arthur Engstrom | 44 | Head | Chauffeur | Illinois |
| 73 | Helen B. Engstrom | 39 | Wife | Radio Assembler | Illinois |
| 74 | Vernon Olsen | 33 | Head | Truck Driver | Illinois |
| 75 | Mary Olsen THIS PERSON | 33 | Wife | — | Illinois |
| 76 | Vernon Olsen | 14 | Son | — | Illinois |
| 77 | Donald Olsen | 12 | Son | — | Illinois |
| 78 | William Olsen | 9 | Son | — | Illinois |
| 79 | Jean Olsen | 6 | Daughter | — | Illinois |
| 80 | Robert Whitman | 58 | Lodger | Electrician | Virginia |
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)