MO
Mary Olsen — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Winnebago-County, Illinois
Our Model Tree links this Mary Olsen across the 1930 and 1940 US Censuses in Winnebago-County, Illinois (XGBoost, ~Confirmed) — first a daughter (b.~1929), then head of a 6-person household.
Age 11
b. ~1929
Female
Daughter
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Winnebago-County, Illinois |
| Surname | Olsen |
| Given Name | Mary L. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Rockford City |
| 1935 Residence (County) | Winnebago |
| Additional Details | |
| Highest Grade | No 5 |
| 1935 Residence | Same House |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Rockford City |
| Est. Birth Year | ~1929 |
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.
6 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| John Olsen | Son | — | 15 | ~1925 |
| Robert Olsen | Son | — | 20 | ~1920 |
| Alma Olsen | Spouse | — | 46 | ~1894 |
| Mary Olsen | Daughter | — | 11 | ~1929 |
| Eckel Olsen | Head | — | 45 | ~1895 |
| Alan Ireland | Other | — | 69 | ~1871 |
Census Appearances
1930
Winnebago, Illinois
Daughter, age 1
Winnebago, Illinois · implied b. ~1929 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Olson |
| Given Name | Mary L. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 1 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Illinois |
| Mother's Birthplace | Sweden |
| Occupation | none |
| Can Read/Write | No |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Winnebago-County, Illinois
Daughter, age 11
Winnebago-County, Illinois · implied b. ~1929 — 6 household members
| Surname | Olsen |
| Given Name | Mary L. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Rockford City |
| 1935 Residence (County) | Winnebago |
| Highest Grade | No 5 |
| 1935 Residence | Same House |
| 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
Daughter · 1940 · age 11 · b. ~1929 · Illinois
★ You are viewing this record
Sibling
Robert Olsen
Sibling · 1940 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Olsen
Sibling · 1940 · age 15
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 — Winnebago-County, Illinois
Open full size
1940 US Federal Census — Winnebago-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00915-00130)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Stanley Ralston | 32 | Head | Assistant Manager | Illinois |
| 42 | Mary H. Ralston | 35 | Wife | Bank Clerk | Indiana |
| 43 | Frances Ralston | 58 | Mother | — | N. Dakota |
| 44 | Edwin R. Johnson | 45 | Head | Glass Cutter | Illinois |
| 45 | Esther S. Johnson | 52 | Wife | — | Illinois |
| 46 | Geraldine Johnson | 14 | Daughter | — | Illinois |
| 47 | Raymond Boise | 32 | Head | Dry Cleaner | Belgium |
| 48 | Harriet L. Boise | 30 | Wife | — | Illinois |
| 49 | Susan C. Boise | 3 | Daughter | — | Illinois |
| 50 | Selma Lindstrom | 63 | Head | — | Illinois |
| 51 | Hazel V. Lindstrom | 36 | Daughter | — | Illinois |
| 52 | Russell V. Lindstrom | 30 | Son | Truck Driver | Illinois |
| 53 | Esther Johnson | 23 | Niece | A Manager Confectioner | Illinois |
| 54 | Martin Anderson | 30 | Head | Office Clerk | Illinois |
| 55 | Kathryn Anderson | 30 | Wife | — | Illinois |
| 56 | Emma Vauter | 76 | Head | — | Sweden |
| 57 | Albert Ekeberg | 55 | Head | Dry Cleaner & Clerk | Illinois |
| 58 | Hilda Ekeberg | 56 | Wife | — | Illinois |
| 59 | John Ekeberg | 28 | Son | Social Science Teacher | Illinois |
| 60 | David J. Corey | 26 | Head | Shaper | Illinois |
| 61 | Ethel Corey | 30 | Wife | — | Illinois |
| 62 | Wendell Mcwilliams | 22 | Head | Asst Foreman | Illinois |
| 63 | Betty A. Mcwilliams | 20 | Wife | House | Sweden |
| 64 | Emma Applequist | 81 | Head | — | Sweden |
| 65 | Richard Applequist | 47 | Son | Laborer | Sweden |
| 66 | Eckel R. Olsen | 45 | Head | Deputy Sheriff | Illinois |
| 67 | Alma C. Olsen | 46 | Wife | Photo Finisher | Sweden |
| 68 | Robert E. Olsen | 20 | Son | Draftsman Apprentice | Illinois |
| 69 | John M. Olsen | 15 | Son | — | Illinois |
| 70 | Mary L. Olsen THIS PERSON | 11 | Daughter | — | Illinois |
| 71 | Alan J. Ireland | 69 | Lodger | — | Illinois |
| 72 | Gust A. Anderson | 67 | Head | Packing Worker | Sweden |
| 73 | Mary E. Anderson | 67 | Wife | — | Sweden |
| 74 | August Sterner | 60 | Head | Bricklayer | Sweden |
| 75 | Johanna D. Sterner | 67 | Wife | — | Sweden |
| 76 | Anna A. Sterner | 40 | Daughter | Office Clerk | Sweden |
| 77 | Arnold Sterner | 35 | Son | Electric Logger | Illinois |
| 78 | Carl G. Lofstedt | 40 | Head | Auto Salesman | Illinois |
| 79 | Elvira E. Lofstedt | 37 | Wife | Telephone Operator | Illinois |
| 80 | William Bliese | 70 | Head | — | 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)