MP
Mary Peterson — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Mary Peterson across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a head (b.~1869), then head of a 2-person household.
Age 71
b. ~1869
Female
Head
Born: Norway
Widowed
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Peterson |
| Given Name | Mary |
| Relationship to Head | Head |
| Sex | F |
| Color / Race | White |
| Age | 71 |
| Marital Status | Widowed |
| Birthplace | Norway |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Naturalization Status | Naturalized |
| Additional Details | |
| Hours Worked | 0 |
| Income (1939) | 0 |
| Highest Grade | No 7 |
| 1935 Residence | Same Place |
| Birth Country | Norway |
| Birthplace (normalized) | norway |
| Township / Ward | Chicago |
| Est. Birth Year | ~1869 |
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.
2 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Mary Peterson | Head | — | 71 | ~1869 |
| Lawrence Peterson | Son | — | 31 | ~1909 |
Census Appearances
1920
Cook, Illinois
Head, age 52
Cook, Illinois · implied b. ~1868 — 2 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Peterson |
| Given Name | Maria |
| Relationship to Head | Head |
| Sex | F |
| Color / Race | White |
| Age | 52 |
| Marital Status | Widowed |
| Birthplace | Norway |
| Year of Immigration | 1872 |
| Naturalization Status | Naturalized |
| Father's Birthplace | Norway |
| Mother's Birthplace | Norway |
| Occupation | none |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | Norwegian |
| Home Owned/Rented | O |
| Home Free/Mortgaged | F |
| Birth Country | Norway |
| Birthplace (normalized) | norway |
1930
Cook, Illinois
Head, age 61
Cook, Illinois · implied b. ~1869 — 2 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Peterson |
| Given Name | Mary |
| Relationship to Head | Head |
| Sex | F |
| Color / Race | White |
| Age | 61 |
| Marital Status | Widowed |
| Birthplace | Norway |
| Naturalization Status | Naturalized |
| Year of Immigration | 1881 |
| Age at First Marriage | 20 |
| Father's Birthplace | Norway |
| Mother's Birthplace | Norway |
| Can Read/Write | Yes |
| Mother Tongue | Norwegian |
| Home Owned/Rented | R |
| Home Value / Rent | 20 |
| Birth Country | Norway |
| Birthplace (normalized) | norway |
1940
Cook-County, Illinois
Head, age 71
Cook-County, Illinois · implied b. ~1869 — 2 household members
| Surname | Peterson |
| Given Name | Mary |
| Relationship to Head | Head |
| Sex | F |
| Color / Race | White |
| Age | 71 |
| Marital Status | Widowed |
| Birthplace | Norway |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Naturalization Status | Naturalized |
| Hours Worked | 0 |
| Income (1939) | 0 |
| Highest Grade | No 7 |
| 1935 Residence | Same Place |
| Birth Country | Norway |
| Birthplace (normalized) | norway |
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 Peterson across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
Mary Peterson
Head · 1940 · age 71 · b. ~1869 · 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-t0627-00990-00563)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | John Rowley | 76 | Head | — | Scotland |
| 42 | Anna Rowley | 68 | Wife | — | Germany |
| 43 | Mildred Scanlon | 43 | Head | — | Illinois |
| 44 | Marie Duncan | 64 | Head | — | Germany |
| 45 | Charles Mcclellan | 81 | Lodger | — | England |
| 46 | Sigurd Swenson | 50 | Lodger | Janitor | Illinois |
| 47 | Joseph Belenka | 41 | Head | Cabinet Maker | Illinois |
| 48 | Marie Belenka | 34 | Wife | — | Poland |
| 49 | Evelyn Belenka | 16 | Daughter | — | Illinois |
| 50 | Joseph Jr. Belenka | 9 | Son | — | Illinois |
| 51 | Richard Belenka | 5 | Son | — | Illinois |
| 52 | John O'Kneffin | 42 | Head | Painter | Illinois |
| 53 | Marie O'Kneffin | 39 | Wife | — | Illinois |
| 54 | Edward O'Kneffin | 17 | Son | New Worker | Illinois |
| 55 | Eric Catling | 34 | Head | Tool Keeper | Illinois |
| 56 | Irene Catling | 29 | Wife | Bartender | Illinois |
| 57 | Dorothy Catling | 20 | Sister-in-law | Wrapper | Illinois |
| 58 | Mary Peterson THIS PERSON | 71 | Head | — | Norway |
| 59 | Lawrence Peterson | 31 | Son | — | Illinois |
| 60 | George Mcguire | 44 | Head | Laborer | Illinois |
| 61 | Helen Mcguire | 40 | Wife | — | Illinois |
| 62 | George Mcguire | 6 | Son | — | Illinois |
| 63 | Charles Nassa | 19 | Son-in-law | New Worker | Illinois |
| 64 | David Tolely | 18 | Lodger | New Worker | Scotland |
| 65 | George Davis | 55 | Head | Carpenter | Massachusetts |
| 66 | Minnie Davis | 61 | Wife | — | Maryland |
| 67 | Frank Lager | 35 | Head | Foreman | Illinois |
| 68 | Theresa Lager | 28 | Wife | — | Illinois |
| 69 | Kenneth Lager | 1 | Son | — | Illinois |
| 70 | Arlene Lager | 1 | Daughter | — | Illinois |
| 71 | John W. Fladera | 47 | Head | Woodworker | Illinois |
| 72 | Lillian Fladera | 44 | Wife | — | Illinois |
| 73 | Richard Fladera | 21 | Son | Shipping Clerk | Illinois |
| 74 | Anna Hugatt | 66 | Mother-in-law | — | Austria |
| 75 | John Southern | 72 | Head | — | England |
| 76 | Agnes Southern | 76 | Wife | — | Switzerland |
| 77 | Agnes Hauschild | 34 | Head | — | Illinois |
| 78 | James O'Brien | 53 | Head | Sheet Metal Worker | Illinois |
| 79 | Mary O'Brien | 42 | Wife | — | Ireland |
| 80 | James O'Brien | 18 | Son | Assistant Shipping Clerk | 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)