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Mary Lopez — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Mary Lopez across the 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a daughter (b.~1924), then head of a 7-person household.
Age 16
b. ~1924
Female
Daughter
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Lopez |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 16 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Industry | 0 |
| Highest Grade | No 7 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1924 |
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 |
|---|---|---|---|---|
| Richard Lopez | Son | — | 10 | ~1930 |
| Joann Lopez | Spouse | — | 42 | ~1898 |
| Rose Lopez | Daughter | — | 15 | ~1925 |
| Peter Lopez | Head | — | 43 | ~1897 |
| Boniface Lopez | Daughter | — | 18 | ~1922 |
| Mary Lopez | Daughter | — | 16 | ~1924 |
| Esther Lopez | Daughter | — | 13 | ~1927 |
Census Appearances
1930
Cook, Illinois
Daughter, age 5
Cook, Illinois · implied b. ~1925
●
Primary link
· ~Confirmed · 1 source
XGBoost
| Surname | Lopez |
| Given Name | Mildred |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 5 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Michigan |
| Mother's Birthplace | Indiana |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Daughter, age 16
Cook-County, Illinois · implied b. ~1924 — 7 household members
| Surname | Lopez |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 16 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Industry | 0 |
| Highest Grade | No 7 |
| 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 Lopez across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Lopez
Daughter · 1940 · age 16 · b. ~1924 · Illinois
★ You are viewing this record
Sibling
Esther Lopez
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Rose Lopez
Sibling · 1940 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Boniface Lopez
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Richard Lopez
Sibling · 1940 · age 10
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 — 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-t0627-00941-00223)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Eugene Powidzki | 6 | Son | — | Illinois |
| 2 | Irene Powidzki | 26 | Head | Laborer | Illinois |
| 3 | Bettie Powidzki | 25 | Wife | — | Illinois |
| 4 | Shirley Ann Powidzki | 4 | Daughter | — | Illinois |
| 5 | Norbert Powidzki | 2 | Son | — | Illinois |
| 6 | Charlotte Witulski | 57 | Head | — | Poland |
| 7 | Ziggie Witulski | 25 | Son | Laborer | Illinois |
| 8 | Harry Witulski | 23 | Son | — | Illinois |
| 9 | Mitchell Witulski | 27 | Head | Sweeper | Illinois |
| 10 | Bernice Witulski | 20 | Wife | — | Illinois |
| 11 | Bernadine Witulski | 2 | Daughter | — | Illinois |
| 12 | Edward Tatarinski | 25 | Head | Laborer | Illinois |
| 13 | Irene Tatarinski | 19 | Wife | — | Illinois |
| 14 | Mary Tatarinski | 0 | Daughter | — | Illinois |
| 15 | Joseph Palacik | 27 | Head | Testing Cars | Illinois |
| 16 | Sophie Palacik | 27 | Wife | — | Illinois |
| 17 | Sylvia Palacik | 7 | Daughter | — | Illinois |
| 18 | Casper Palacik | 3 | Son | — | Illinois |
| 19 | John Bargajewicz | 53 | Head | Watchman | Poland |
| 20 | Blanche Bargajewicz | 50 | Wife | — | Poland |
| 21 | Peter Lopez | 43 | Head | Laborer | Mexico |
| 22 | Joann Lopez | 42 | Wife | — | Mexico |
| 23 | Boniface Lopez | 18 | Daughter | — | Mexico |
| 24 | Mary Lopez THIS PERSON | 16 | Daughter | — | Illinois |
| 25 | Rose Lopez | 15 | Daughter | — | Illinois |
| 26 | Esther Lopez | 13 | Daughter | — | Illinois |
| 27 | Richard Lopez | 10 | Son | — | Illinois |
| 28 | Frank Bardyalak | 48 | Head | Cook | Poland |
| 29 | Joe Malladi | 49 | Boarder | Chipper | Poland |
| 30 | Pedro Tovar | 39 | Head | Laborer | Mexico |
| 31 | Alice Tovar | 15 | Wife | — | Mexico |
| 32 | Magdalena Tovar | 11 | Daughter | — | Illinois |
| 33 | Eliseo Tesaro | 58 | Head | Laborer | Mexico |
| 34 | Mary Tesaro | 41 | Wife | — | Mexico |
| 35 | Juanita Tesaro | 10 | Daughter | — | Illinois |
| 36 | Rachel Tesaro | 9 | Daughter | — | Illinois |
| 37 | Ray Tesaro | 8 | Son | — | Illinois |
| 38 | Delores Tesaro | 5 | Daughter | — | Illinois |
| 39 | Valen Tesaro | 4 | Daughter | — | Illinois |
| 40 | Nicolas Tesaro | 3 | 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)