MK
Mary Kelly — 1940 US Census Record
Model Tree available1940 United States Federal Census · Middlesex-County, Massachusetts
Our Model Tree links this Mary Kelly across the 1920, 1930 and 1940 US Censuses in Middlesex-County, Massachusetts (XGBoost, ~Confirmed), with identified parents John & John — first a daughter (b.~1919), then head of a 8-person household.
Age 21
b. ~1919
Female
Daughter
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Middlesex-County, Massachusetts |
| Surname | Kelly |
| Given Name | Mary R. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Watertown town |
| 1935 Residence (County) | Middlesex |
| Additional Details | |
| Occupation | Comptometer |
| Industry | Chemical works |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 938 |
| Highest Grade | H-4 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Comptometer |
| Township / Ward | Watertown Town |
| Est. Birth Year | ~1919 |
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 |
|---|---|---|---|---|
| Mary Kelly | Daughter | — | 21 | ~1919 |
| Louise Kelly | Daughter | — | 22 | ~1918 |
| Leslie Kelly | Daughter | — | 6 | ~1934 |
| Patricia Kelly | Daughter | — | 10 | ~1930 |
| Francis Kelly | Daughter | — | 12 | ~1928 |
| John Kelly | Head | — | 50 | ~1890 |
| John Kelly | Son | — | 15 | ~1925 |
| Agnes Kelly | Spouse | — | 49 | ~1891 |
Census Appearances
1920
Middlesex, Massachusetts
Daughter, age 1
Middlesex, Massachusetts · implied b. ~1919 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kelly |
| Given Name | Mary R. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 1 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1930
Middlesex, Massachusetts
Daughter, age 11
Middlesex, Massachusetts · implied b. ~1919 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kelly |
| Given Name | Mary R |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Occupation | none |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Middlesex-County, Massachusetts
Daughter, age 21
Middlesex-County, Massachusetts · implied b. ~1919 — 8 household members
| Surname | Kelly |
| Given Name | Mary R. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Watertown town |
| 1935 Residence (County) | Middlesex |
| Occupation | Comptometer |
| Industry | Chemical works |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 938 |
| Highest Grade | H-4 |
| 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 Kelly across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father John Kelly (~0.92 confidence) and father John Kelly (~0.92 confidence) and father Edward Kelly (~0.92 confidence) and mother Agnes Kelly (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
John Kelly
b. ~1890
Source father
● Household
· direct · ~0.92
Father
John Kelly
b. ~1890
Source father
● Household
· direct · ~0.92
Father
Edward Kelly
b. ~1891
Source father
● Household
· direct · ~0.92
Mother
Agnes Kelly
b. ~1892
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Mary Kelly
Daughter · 1940 · age 21 · b. ~1919 · Massachusetts
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Sibling
Leslie Kelly
Sibling · 1940 · age 6
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Louise Kelly
Sibling · 1940 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Francis Kelly
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Kelly
Sibling · 1940 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Patricia Kelly
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 — 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-t0627-01621-00225)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Chester N. Parker | 32 | Head | Clerk | Rhode Island |
| 2 | Eleanor R. Parker | 28 | Wife | — | Massachusetts |
| 3 | Chester N. Jr. Parker | 8 | Son | — | Massachusetts |
| 4 | Beverly A. Parker | 5 | Daughter | — | Massachusetts |
| 5 | Eleanor E. Parker | 4 | Daughter | — | Massachusetts |
| 6 | Misak G. Selian | 37 | Head | Leather Dealer | Turkey |
| 7 | Yerkin T. Selian | 31 | Wife | — | Massachusetts |
| 8 | Diana M. Selian | 6 | Daughter | — | Massachusetts |
| 9 | Gloria V. Selian | 3 | Daughter | — | Massachusetts |
| 10 | John W. Kelly | 50 | Head | Foreman Machinist | Massachusetts |
| 11 | Agnes T. Kelly | 49 | Wife | — | Massachusetts |
| 12 | Louise A. Kelly | 22 | Daughter | Tv Secretary | Massachusetts |
| 13 | Mary R. Kelly THIS PERSON | 21 | Daughter | Comptometer | Massachusetts |
| 14 | John W. Jr. Kelly | 15 | Son | — | Massachusetts |
| 15 | Francis A. Kelly | 12 | Daughter | — | Massachusetts |
| 16 | Patricia Kelly | 10 | Daughter | — | Massachusetts |
| 17 | Leslie J. Kelly | 6 | Daughter | — | Massachusetts |
| 18 | Arthur J. Hasson | 47 | Head | Tree Supervisor | Massachusetts |
| 19 | Mary A. Hasson | 41 | Wife | — | Canada English |
| 20 | Jean M. Hasson | 12 | Daughter | — | Massachusetts |
| 21 | Mary E. Hasson | 10 | Daughter | — | Massachusetts |
| 22 | Rita F. Hasson | 8 | Daughter | — | Massachusetts |
| 23 | Barbara A. Hasson | 4 | Daughter | — | Massachusetts |
| 24 | Charles R. Fox | 38 | Head | Machinist | Connecticut |
| 25 | Marjorie R. Fox | 35 | Wife | — | England |
| 26 | Helen M. Fox | 17 | Daughter | — | Connecticut |
| 27 | Nancy J. Fox | 12 | Daughter | — | Connecticut |
| 28 | Charles R. Jr. Fox | 9 | Son | — | Connecticut |
| 29 | Nathaniel C. Sawyer | 45 | Head | Carpenter | Massachusetts |
| 30 | Laura L. Sawyer | 38 | Wife | — | Massachusetts |
| 31 | Ruth N. Sawyer | 17 | Daughter | — | Massachusetts |
| 32 | Constance M. Sawyer | 13 | Daughter | — | Massachusetts |
| 33 | Vital B. Therreault | 65 | Lodger | Machinist | Canada French |
| 34 | John A. Garland | 37 | Head | Office Manager | Massachusetts |
| 35 | Florence A. Garland | 30 | Wife | — | Rhode Island |
| 36 | John A. Jr. Garland | 4 | Son | — | Massachusetts |
| 37 | Joseph Santoro | 50 | Head | Barber | Italy |
| 38 | Bessie Santoro | 48 | Wife | — | Italy |
| 39 | John J. Santoro | 26 | Son | Barber | Massachusetts |
| 40 | Nicholas F. Santoro | 25 | Son | Floor Man | Massachusetts |
Related Census Records
Pedigree Summary
Mary + 5 siblings
Gen 1 · 4 parents
~0.92
Max depth 4 (1900–1950 window)
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)