MH
Mary Hardy — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Middlesex-County, Massachusetts
Our Model Tree links this Mary Hardy across the 1930 and 1940 US Censuses in Middlesex-County, Massachusetts (XGBoost, ~Confirmed) — first a daughter (b.~1924), then head of a 12-person household.
Age 16
b. ~1924
Female
Daughter
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Middlesex-County, Massachusetts |
| Surname | Hardy |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 16 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Somerville city |
| 1935 Residence (County) | Middlesex |
| Additional Details | |
| Class of Worker | 0 |
| Highest Grade | Hs 2 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Township / Ward | Somerville 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.
12 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Irene Hardy | Daughter | — | 3 | ~1937 |
| Mary Hardy | Daughter | — | 16 | ~1924 |
| Walter Hardy | Head | — | 45 | ~1895 |
| John Hardy | Son | — | 18 | ~1922 |
| Edward Hardy | Son | — | 23 | ~1917 |
| Alfred Hardy | Son | — | 13 | ~1927 |
| Francis Hardy | Son | — | 6 | ~1934 |
| James Hardy | Son | — | 10 | ~1930 |
| Robert Hardy | Son | — | 21 | ~1919 |
| George Hardy | Son | — | ~1940 | |
| William Hardy | Son | — | 11 | ~1929 |
| Mary Hardy | Spouse | — | 41 | ~1899 |
Census Appearances
1930
Middlesex, Massachusetts
Daughter, age 5
Middlesex, Massachusetts · implied b. ~1925 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Hardy |
| Given Name | Mary L |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 5 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Maine |
| Occupation | none |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Middlesex-County, Massachusetts
Daughter, age 16
Middlesex-County, Massachusetts · implied b. ~1924 — 12 household members
| Surname | Hardy |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 16 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Somerville city |
| 1935 Residence (County) | Middlesex |
| Class of Worker | 0 |
| Highest Grade | Hs 2 |
| 1935 Residence | Same place |
| 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 Hardy across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Hardy
Daughter · 1940 · age 16 · b. ~1924 · Massachusetts
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Sibling
Francis Hardy
Sibling · 1940 · age 6
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
William Hardy
Sibling · 1940 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Hardy
Sibling · 1940 · age 23
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Alfred Hardy
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Irene Hardy
Sibling · 1940 · age 3
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
James Hardy
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Hardy
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Robert Hardy
Sibling · 1940 · age 21
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
George Hardy
Sibling · 1940 · age
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-t0627-01702-00551)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Jessie Simas | 31 | Head | Upholstery | Massachusetts |
| 2 | Anna Simas | 30 | Wife | Shoe Stitcher | Massachusetts |
| 3 | Ernest Ribeiro | 20 | Head | Laborer | Massachusetts |
| 4 | Maria Ribeiro | 52 | Mother | — | Portugal |
| 5 | Rita Ribeiro | 15 | Sister | — | Massachusetts |
| 6 | Michael Buckley | 61 | Head | Stat. Engineer | Irish Free St |
| 7 | Mary Buckley | 60 | Wife | — | Irish Free St |
| 8 | Martin Bakey | 65 | Boarder | Laborer | Irish Free St |
| 9 | Edward Preston | 30 | Head | Shipping Clerk | Massachusetts |
| 10 | Margaret Preston | 22 | Wife | — | Massachusetts |
| 11 | Josephine Preston | 3 | Daughter | — | Massachusetts |
| 12 | Stephen Preston | 2 | Son | — | Massachusetts |
| 13 | Walter Hardy | 45 | Head | Fireman | Massachusetts |
| 14 | Mary Hardy | 41 | Wife | — | Massachusetts |
| 15 | Edward Hardy | 23 | Son | Hot Oilers | Massachusetts |
| 16 | Robert Hardy | 21 | Son | Hot Oilers | Massachusetts |
| 17 | John Hardy | 18 | Son | — | Massachusetts |
| 18 | Mary Hardy THIS PERSON | 16 | Daughter | — | Massachusetts |
| 19 | Alfred Hardy | 13 | Son | — | Massachusetts |
| 20 | William Hardy | 11 | Son | — | Massachusetts |
| 21 | James Hardy | 10 | Son | — | Massachusetts |
| 22 | Francis Hardy | 6 | Son | — | Massachusetts |
| 23 | Irene Hardy | 3 | Daughter | — | Massachusetts |
| 24 | George Hardy | 0 | Son | — | Massachusetts |
| 25 | James Keating | 42 | Head | Furniture Finisher | Irish Free St |
| 26 | Teresa Keating | 39 | Wife | — | Irish Free St |
| 27 | John Keating | 18 | Son | Upholsterer | Massachusetts |
| 28 | James Keating | 17 | Son | — | Massachusetts |
| 29 | Margaret Keating | 14 | Daughter | — | Massachusetts |
| 30 | Frank Collins | 35 | Head | Truck Driver | Massachusetts |
| 31 | Mary Collins | 31 | Wife | — | Massachusetts |
| 32 | Bobby Collins | 6 | Son | — | Massachusetts |
| 33 | Jack Collins | 3 | Son | — | Massachusetts |
| 34 | Mary T. O'Meara | 23 | Boarder | Telephone Operator | Massachusetts |
| 35 | Michael J. Doyle | 66 | Head | Laborer | Irish Free St |
| 36 | Catherine Doyle | 30 | Daughter | Steno. | Massachusetts |
| 37 | Mary Moran | 33 | Niece | Telep Sup. | Massachusetts |
| 38 | Margaret Moran | 31 | Niece | Telep. Operator | Massachusetts |
| 39 | Anthony Principe | 29 | Head | Auto Mechanic | Italy |
| 40 | Catherine Principe | 27 | Wife | — | Massachusetts |
Related Census Records
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)