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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.~1926), then head of a 8-person household.
Age 14
b. ~1926
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 | 14 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Class of Worker | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Chicago |
| Est. Birth Year | ~1926 |
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.
8 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Josephine Lopez | Daughter | — | 8 | ~1932 |
| Manuella Lopez | Spouse | — | 36 | ~1904 |
| John Lopez | Head | — | 40 | ~1900 |
| John Lopez | Son | — | 6 | ~1934 |
| Alice Lopez | Daughter | — | 16 | ~1924 |
| Jessie Lopez | Son | — | 18 | ~1922 |
| Antonia Lopez | Daughter | — | 9 | ~1931 |
| Mary Lopez | Daughter | — | 14 | ~1926 |
Census Appearances
1930
Cook, Illinois
Daughter, age 3
Cook, Illinois · implied b. ~1927 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Lopez |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 3 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Spain |
| Mother's Birthplace | Spain |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Daughter, age 14
Cook-County, Illinois · implied b. ~1926 — 8 household members
| Surname | Lopez |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Class of Worker | 0 |
| 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 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 14 · b. ~1926 · Illinois
★ You are viewing this record
Sibling
Antonia Lopez
Sibling · 1940 · age 9
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Alice Lopez
Sibling · 1940 · age 16
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Jessie Lopez
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Lopez
Sibling · 1940 · age 6
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Josephine Lopez
Sibling · 1940 · age 8
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-t0627-00921-00542)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Anna Stephan | 7 | Granddaughter | — | Illinois |
| 2 | Phillip Stephan | 3 | Grandson | — | Illinois |
| 3 | Hong Yong | 51 | Head | Office Clerk | China |
| 4 | Mary Yong | 50 | Wife | — | Illinois |
| 5 | Rocco De Capo | 55 | Head | Laborer | Italy |
| 6 | Carmella De Capo | 55 | Wife | — | Illinois |
| 7 | Michel De Capo | 32 | Son | Grocery Clerk | Illinois |
| 8 | Thomas De Capo | 27 | Son | Paper Boy | Illinois |
| 9 | Mary De Capo | 24 | Daughter | — | Illinois |
| 10 | Anthony De Capo | 22 | Son | Grocery Clerk | Illinois |
| 11 | Charlie De Capo | 18 | Son | Laborer | Illinois |
| 12 | Adeline Cox | 62 | Head | — | Mississippi |
| 13 | John Dean | 66 | Lodger | — | Georgia |
| 14 | Matilda Thomas | 38 | Head | Maid | Virginia |
| 15 | Bertha Thomas | 17 | Daughter | — | Virginia |
| 16 | Ethaline Thomas | 16 | Daughter | — | Virginia |
| 17 | Geraldine Thomas | 15 | Daughter | — | Virginia |
| 18 | Samuel Thomas | 13 | Son | — | Virginia |
| 19 | Dionisio Palma | 55 | Head | Proprietor | Italy |
| 20 | Nancy Palma | 59 | Wife | — | Italy |
| 21 | Angela Palma | 18 | Daughter | Machine Operator | Illinois |
| 22 | Ollie Rodgers | 36 | Head | — | Mississippi |
| 23 | Kelly Moore | 43 | Lodger | Common Labor | Mississippi |
| 24 | John Lopez | 40 | Head | Common Labor | Mexico |
| 25 | Manuella Lopez | 36 | Wife | — | Mexico |
| 26 | Jessie Lopez | 18 | Son | — | Texas |
| 27 | Alice Lopez | 16 | Daughter | — | Minnesota |
| 28 | Mary Lopez THIS PERSON | 14 | Daughter | — | Illinois |
| 29 | Antonia Lopez | 9 | Daughter | — | Illinois |
| 30 | Josephine Lopez | 8 | Daughter | — | Illinois |
| 31 | John Lopez | 6 | Son | — | Illinois |
| 32 | Carl Leon | 36 | Head | Common Laborer | Spain |
| 33 | Josephine Leon | 28 | Wife | Labeler | Illinois |
| 34 | Joseph Leon | 3 | Son | — | Illinois |
| 35 | Nicholas Pintozi | 52 | Head | Office Clerk | Illinois |
| 36 | Mary Pintozi | 42 | Wife | — | Italy |
| 37 | Phillip Daleome | 34 | Head | Salesman | Illinois |
| 38 | Marion Daleome | 32 | Wife | — | Illinois |
| 39 | Macario Nambo | 45 | Head | — | Mexico |
| 40 | Ethel Nambo | 44 | Wife | — | Pennsylvania |
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)