ML
Mary Lopez — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Middlesex-County, Massachusetts
Our Model Tree links this Mary Lopez across the 1930 and 1940 US Censuses in Middlesex-County, Massachusetts (XGBoost, ~Confirmed) — first a daughter (b.~1911), then head of a 9-person household.
Age 29
b. ~1911
Female
Daughter
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Middlesex-County, Massachusetts |
| Surname | Lopez |
| Given Name | Mary V |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 29 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Somerville city |
| 1935 Residence (County) | Middlesex |
| Additional Details | |
| Occupation | Shaker |
| Industry | Laundry |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 625 |
| Highest Grade | Hs 3 |
| 1935 Residence | Same house |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Shaker |
| Township / Ward | Somerville City |
| Est. Birth Year | ~1911 |
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.
9 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Adelaide Lopez | Daughter | — | 17 | ~1923 |
| Louise Lopez | Daughter | — | 23 | ~1917 |
| Manuel Lopez | Head | — | 56 | ~1884 |
| James Lopez | Son | — | 19 | ~1921 |
| Evelyn Lopez | Daughter | — | 14 | ~1926 |
| Mary Lopez | Daughter | — | 29 | ~1911 |
| Adelaide Lopez | Spouse | — | 52 | ~1888 |
| Irene Lopez | Daughter | — | 28 | ~1912 |
| Lillian Lopez | Daughter | — | 22 | ~1918 |
Census Appearances
1930
Middlesex, Massachusetts
Daughter, age 18
Middlesex, Massachusetts · implied b. ~1912 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Lopez |
| Given Name | Mary L |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 18 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Portugal |
| Mother's Birthplace | Massachusetts |
| Occupation | Shipper |
| Industry | Candy factory |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Middlesex-County, Massachusetts
Daughter, age 29
Middlesex-County, Massachusetts · implied b. ~1911 — 9 household members
| Surname | Lopez |
| Given Name | Mary V |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 29 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Somerville city |
| 1935 Residence (County) | Middlesex |
| Occupation | Shaker |
| Industry | Laundry |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 625 |
| Highest Grade | Hs 3 |
| 1935 Residence | Same house |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
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 29 · b. ~1911 · Massachusetts
★ You are viewing this record
Sibling
Irene Lopez
Sibling · 1940 · age 28
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
James Lopez
Sibling · 1940 · age 19
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Adelaide Lopez
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Lillian Lopez
Sibling · 1940 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Louise Lopez
Sibling · 1940 · age 23
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Evelyn Lopez
Sibling · 1940 · age 14
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 — Middlesex-County, Massachusetts
Open full size
1940 US Federal Census — Middlesex-County, Massachusetts
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01705-00411)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Eleanor Chisholm | 10 | Daughter | — | Massachusetts |
| 42 | Jean Chisholm | 7 | Daughter | — | Massachusetts |
| 43 | John C Bicknell | 57 | Head | Time Table Constructor | New York |
| 44 | Gertrude M Bicknell | 47 | Wife | — | Massachusetts |
| 45 | Walter C Bicknell | 22 | Son | New Worker | Massachusetts |
| 46 | Mary A Goran | 66 | Head | — | Massachusetts |
| 47 | Helen V Moore | 53 | Sister | Box Maker | Massachusetts |
| 48 | Percy D Baker | 55 | Head | Operator | Canada |
| 49 | Kathleen Baker | 52 | Wife | — | New Hampshire |
| 50 | Charles L Baker | 21 | Son | — | Massachusetts |
| 51 | Lillian M Smith | 75 | Mother | — | New Hampshire |
| 52 | George Morrison | 39 | Head | Painter | Scotland |
| 53 | Robertina Morrison | 35 | Wife | — | Scotland |
| 54 | Manuel Lopez | 56 | Head | Painter | Portugal |
| 55 | Adelaide Lopez | 52 | Wife | — | Portugal |
| 56 | Mary V Lopez THIS PERSON | 29 | Daughter | Shaker | Massachusetts |
| 57 | Irene Lopez | 28 | Daughter | Box Maker | Massachusetts |
| 58 | Louise Q Lopez | 23 | Daughter | Servant | Massachusetts |
| 59 | Lillian Lopez | 22 | Daughter | Shaker | Massachusetts |
| 60 | James W Lopez | 19 | Son | Painter | Massachusetts |
| 61 | Adelaide Lopez | 17 | Daughter | — | Massachusetts |
| 62 | Evelyn Lopez | 14 | Daughter | — | Massachusetts |
| 63 | Zach Agabedian | 44 | Head | Proprietor | Turkey |
| 64 | Mary Agabedian | 40 | Wife | — | Turkey |
| 65 | Gaspella Agabedian | 13 | Daughter | — | Greece |
| 66 | Elizabeth Agabedian | 11 | Daughter | — | Greece |
| 67 | Ruth Agabedian | 9 | Daughter | — | Massachusetts |
| 68 | Harry Agabedian | 5 | Son | — | Massachusetts |
| 69 | John Shea | 35 | Head | Agent | Massachusetts |
| 70 | Lorraine Shea | 21 | Wife | — | Massachusetts |
| 71 | Barbara Shea | 2 | Daughter | — | Massachusetts |
| 72 | Daniel Mahoney | 31 | Head | Clerical | Massachusetts |
| 73 | Alice Mahoney | 34 | Wife | — | Massachusetts |
| 74 | Mary E Mahoney | 1 | Daughter | — | Massachusetts |
| 75 | John W Bates | 63 | Head | — | England |
| 76 | Henrietta E Bates | 55 | Wife | — | Massachusetts |
| 77 | Warren A Bates | 31 | Son | Salesman | Massachusetts |
| 78 | Henrietta M Bates | 29 | Daughter | Clerical | Massachusetts |
| 79 | Margaret M Bates | 26 | Daughter | Typist | Massachusetts |
| 80 | Norman C Bates | 21 | Son | New Worker | Massachusetts |
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)