MO
Mary Olsen — 1930 US Census Record
Linked across censuses1930 United States Federal Census · Cook, Illinois
Our Model Tree links this Mary Olsen across the 1930 and 1940 US Censuses in Cook, Illinois (XGBoost, ~Confirmed) — first a daughter (b.~1920), then head of a 7-person household.
Age 10
b. ~1920
Female
Daughter
Born: Illinois
Single
1930 Census Record Details
| Census Year | 1930 |
| Location | Cook, Illinois |
| Surname | Olsen |
| Given Name | Mary E. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 10 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Sweden |
| Mother's Birthplace | Canada |
| Additional Details | |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Chicago |
| Est. Birth Year | ~1920 |
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 1930 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Harold Olsen | Son | — | 16 | ~1914 |
| Paul Olsen | Son | — | 14 | ~1916 |
| Mary Olsen | Daughter | — | 10 | ~1920 |
| Castier Olsen | Son | — | 12 | ~1918 |
| Helen Olsen | Daughter | — | 15 | ~1915 |
| Elias Olsen | Head | — | 45 | ~1885 |
| Carrie Olsen | Spouse | — | 49 | ~1881 |
Census Appearances
1930
Cook, Illinois
Daughter, age 10
Cook, Illinois · implied b. ~1920 — 7 household members
| Surname | Olsen |
| Given Name | Mary E. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 10 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Sweden |
| Mother's Birthplace | Canada |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Daughter, age 21
Cook-County, Illinois · implied b. ~1919 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Olson |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Occupation | Secretary |
| Industry | Religious |
| Class of Worker | PW |
| Hours Worked | 44 |
| Income (1939) | 236 |
| Highest Grade | H 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 Olsen across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Olsen
Daughter · 1930 · age 10 · b. ~1920 · Illinois
★ You are viewing this record
Sibling
Harold Olsen
Sibling · 1930 · age 16
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Castier Olsen
Sibling · 1930 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Paul Olsen
Sibling · 1930 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Helen Olsen
Sibling · 1930 · 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
1930 US Federal Census — Cook, Illinois
Open full size
1930 US Federal Census — Cook, Illinois
Page Contents
50 people indexed on this census page (ia:1930:illinoiscensus00reel495:1087)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Helen Baden | 75 | Head | — | Germany |
| 2 | Mary Baden | 55 | Daughter | — | Illinois |
| 3 | Axel Peterson | 58 | Head | Motorman | Denmark |
| 4 | Hulda Peterson | 44 | Wife | — | Denmark |
| 5 | Thorwald Peterson | 18 | Son | — | Illinois |
| 6 | Thomas Houchens | 32 | Head | Salesman | Kentucky |
| 7 | Kathryn Houchens | 32 | Wife | — | New York |
| 8 | Louise Houchens | 1 | Daughter | — | Illinois |
| 9 | Laurence Gruber | 31 | Brother-in-law | Artist | New York |
| 10 | Walter Borgeson | 40 | Head | Salesman | Illinois |
| 11 | Florence Borgeson | 38 | Wife | — | Illinois |
| 12 | June Borgeson | 9 | Daughter | — | Illinois |
| 13 | Donald Borgeson | 7 | Son | — | Illinois |
| 14 | Emma Nelson | 67 | Mother-in-law | — | Sweden |
| 15 | Samuel Halm | 47 | Head | Carpenter | Sweden |
| 16 | Ellen Halm | 43 | Wife | — | Illinois |
| 17 | Evelyn Halm | 20 | Daughter | Clerk | Illinois |
| 18 | Clifford Halm | 18 | Son | Tool-Making | Illinois |
| 19 | Elias Olsen | 45 | Head | Tool-Maker | Sweden |
| 20 | Carrie Olsen | 49 | Wife | — | Canada |
| 21 | Harold Olsen | 16 | Son | — | Illinois |
| 22 | Helen Olsen | 15 | Daughter | — | Illinois |
| 23 | Paul Olsen | 14 | Son | — | Illinois |
| 24 | Castier Olsen | 12 | Son | — | Illinois |
| 25 | Mary E. Olsen THIS PERSON | 10 | Daughter | — | Illinois |
| 26 | George T. Cato | 40 | Head | Salesman | Massachusetts |
| 27 | Matilda Cato | 39 | Wife | — | Illinois |
| 28 | George Jr. Cato | 9 | Son | — | Illinois |
| 29 | Robert Cato | 7 | Son | — | Illinois |
| 30 | Patrick Cato | 72 | Father | — | Rhode Island |
| 31 | Robert Wretshonur | 32 | Head | Contractor | Illinois |
| 32 | Charlotte Wretshonur | 25 | Wife | — | Illinois |
| 33 | Doris Wretshonur | 1 | Daughter | — | Illinois |
| 34 | Lois Wretshonur | 0 | Daughter | — | Illinois |
| 35 | Julius Dickert | 42 | Head | Photographer | Wisconsin |
| 36 | Caroline Dickert | 38 | Wife | — | Illinois |
| 37 | Howard Dickert | 9 | Son | — | Illinois |
| 38 | Joyce Dickert | 7 | Daughter | — | Illinois |
| 39 | Grace Dickert | 7 | Daughter | — | Illinois |
| 40 | Venus Trombley | 16 | Niece | Operator | Illinois |
| 41 | Arthur Helbig | 58 | Head | Bricklayer | Germany |
| 42 | Bertha Helbig | 48 | Wife | — | Germany |
| 43 | Walter Helbig | 24 | Son | Installer | Illinois |
| 44 | Theodore Helbig | 21 | Son | Apprentice | Wisconsin |
| 45 | Frieda Helbig | 14 | Daughter | — | Wisconsin |
| 46 | Amelia Helbig | 9 | Daughter | — | Wisconsin |
| 47 | John Een | 45 | Head | Carpenter | Sweden |
| 48 | Anna Een | 42 | Wife | — | Sweden |
| 49 | Ralph Een | 2 | Son | — | Illinois |
| 50 | Leonard Baumann | 36 | Head | Salesman | Illinois |
About This Record & Model Tree
This record was independently indexed by YourRoots from the 1930 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)