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John Leary — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Middlesex-County, Massachusetts
Our Model Tree links this John Leary across the 1930 and 1940 US Censuses in Middlesex-County, Massachusetts (XGBoost, ~Confirmed) — first a son (b.~1922), then head of a 9-person household.
Age 18
b. ~1922
Male
Son
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Middlesex-County, Massachusetts |
| Surname | Leary |
| Given Name | John M. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 18 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Somerville (City) |
| 1935 Residence (County) | Middlesex |
| Additional Details | |
| Occupation | Houseboy |
| Industry | Private Club |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 370 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Houseboy |
| Township / Ward | Somerville City |
| Est. Birth Year | ~1922 |
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 John | Age | Birth yr |
|---|---|---|---|---|
| Thomas Leary | Son | — | 14 | ~1926 |
| Helen Leary | Daughter | — | 13 | ~1927 |
| Margaret Leary | Spouse | — | 45 | ~1895 |
| Margaret Leary | Daughter | — | 17 | ~1923 |
| Nora Leary | Daughter | — | 11 | ~1929 |
| John Leary | Son | — | 18 | ~1922 |
| Elizabeth Leary | Daughter | — | 8 | ~1932 |
| Marie Leary | Daughter | — | 4 | ~1936 |
| Thomas Leary | Head | — | 50 | ~1890 |
Census Appearances
1930
Middlesex, Massachusetts
Son, age 8
Middlesex, Massachusetts · implied b. ~1922 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Leary |
| Given Name | John M |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 8 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Age at First Marriage | No |
| Father's Birthplace | Irish Free State |
| Mother's Birthplace | Irish Free State |
| Occupation | none |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Middlesex-County, Massachusetts
Son, age 18
Middlesex-County, Massachusetts · implied b. ~1922 — 9 household members
| Surname | Leary |
| Given Name | John M. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 18 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Somerville (City) |
| 1935 Residence (County) | Middlesex |
| Occupation | Houseboy |
| Industry | Private Club |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 370 |
| Highest Grade | Hs 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 John Leary across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Leary
Son · 1940 · age 18 · b. ~1922 · Massachusetts
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Sibling
Margaret Leary
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Nora Leary
Sibling · 1940 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Marie Leary
Sibling · 1940 · age 4
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Thomas Leary
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Helen Leary
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Elizabeth Leary
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 — 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-t0627-01704-00282)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Alice F. Perry | 58 | Wife | — | Canada English |
| 2 | Anthony F. Marino | 45 | Head | Attendant | Italy |
| 3 | Marie E. Marino | 43 | Wife | — | Irish Free State |
| 4 | Marietta B. Marino | 21 | Daughter | Secretary | Massachusetts |
| 5 | Jean F. Marino | 20 | Daughter | Secretary | Massachusetts |
| 6 | Gloria L. Marino | 18 | Daughter | — | Massachusetts |
| 7 | Francis L. Daley | 35 | Head | Record Clerk | Massachusetts |
| 8 | Mary E. Daley | 34 | Wife | — | Massachusetts |
| 9 | Patricia F. Daley | 2 | Daughter | — | Massachusetts |
| 10 | Forrest E. Bartlett | 46 | Head | Motorman | New Hampshire |
| 11 | Ruth M. Bartlett | 42 | Wife | — | Massachusetts |
| 12 | Forrest E. Jr. Bartlett | 18 | Son | — | Massachusetts |
| 13 | Shirley V. Bartlett | 15 | Daughter | — | Massachusetts |
| 14 | William C. Bartlett | 13 | Son | — | Massachusetts |
| 15 | Misto G. Mullin | 69 | Head | — | Albania |
| 16 | Fieftera Mullin | 62 | Wife | — | Albania |
| 17 | Evon Muller | 38 | Son | Baker | Albania |
| 18 | Donald Muller | 14 | Grandson | — | Washington |
| 19 | Nicholas Ktona | 15 | Nephew | — | Albania |
| 20 | Ralph J. Ferullo | 38 | Head | Shoe Cutter | Massachusetts |
| 21 | Josephine M. Ferullo | 38 | Wife | — | Massachusetts |
| 22 | Evelyn P. Ferullo | 12 | Daughter | — | Massachusetts |
| 23 | Irene M. Ferullo | 8 | Daughter | — | Massachusetts |
| 24 | Emma Schwab | 51 | Head | — | Massachusetts |
| 25 | Walter R. Schwab | 25 | Son | Shipper | New York |
| 26 | Lester E. Schwab | 24 | Son | New Worker | New York |
| 27 | Carl F. Parsons | 81 | Head | — | Sweden |
| 28 | Ida A. Parsons | 75 | Wife | — | Sweden |
| 29 | Here End Block 486 And Begins Block 487 | None | — | — | — |
| 30 | Thomas Leary | 50 | Head | Truckman | Irish Free State |
| 31 | Margaret A. Leary | 45 | Wife | — | Irish Free State |
| 32 | John M. Leary THIS PERSON | 18 | Son | Houseboy | Massachusetts |
| 33 | Margaret M. Leary | 17 | Daughter | — | Massachusetts |
| 34 | Thomas J. Leary | 14 | Son | — | Massachusetts |
| 35 | Helen M. Leary | 13 | Daughter | — | Massachusetts |
| 36 | Nora Leary | 11 | Daughter | — | Massachusetts |
| 37 | Elizabeth Leary | 8 | Daughter | — | Massachusetts |
| 38 | Marie Leary | 4 | Daughter | — | Massachusetts |
| 39 | James R. Logan | 65 | Head | Cabinet Maker | Canada English |
| 40 | Emily Logan | 52 | Wife | — | England |
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)