JM
James Mahoney — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Middlesex-County, Massachusetts
Our Model Tree links this James Mahoney across the 1930 and 1940 US Censuses in Middlesex-County, Massachusetts (XGBoost, ~Confirmed) — first a son (b.~1915), then head of a 10-person household.
Age 25
b. ~1915
Male
Son
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Middlesex-County, Massachusetts |
| Surname | Mahoney |
| Given Name | James E |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Somerville city |
| 1935 Residence (County) | Middlesex |
| Additional Details | |
| Occupation | Clerk |
| Industry | Retail Store |
| Class of Worker | PW |
| Hours Worked | 13 |
| Income (1939) | 220 |
| Highest Grade | H-4 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Clerk |
| Township / Ward | Somerville City |
| Est. Birth Year | ~1915 |
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.
10 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to James | Age | Birth yr |
|---|---|---|---|---|
| John Mahoney | Son | — | 35 | ~1905 |
| Henry Mahoney | Son | — | 32 | ~1908 |
| Vincent Mahoney | Son | — | 24 | ~1916 |
| Stephen Mahoney | Son | — | 33 | ~1907 |
| Dennis Mahoney | Head | — | 67 | ~1873 |
| Edward Mahoney | Son | — | 22 | ~1918 |
| Margaret Mahoney | Daughter | — | 34 | ~1906 |
| James Mahoney | Son | — | 25 | ~1915 |
| Philip Mahoney | Son | — | 18 | ~1922 |
| Bridget Mahoney | Spouse | — | 63 | ~1877 |
Census Appearances
1930
Middlesex, Massachusetts
Son, age 12
Middlesex, Massachusetts · implied b. ~1918 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Mahoney |
| Given Name | James A. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Irish Free State |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Middlesex-County, Massachusetts
Son, age 25
Middlesex-County, Massachusetts · implied b. ~1915 — 10 household members
| Surname | Mahoney |
| Given Name | James E |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Somerville city |
| 1935 Residence (County) | Middlesex |
| Occupation | Clerk |
| Industry | Retail Store |
| Class of Worker | PW |
| Hours Worked | 13 |
| Income (1939) | 220 |
| 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 James Mahoney across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
James Mahoney
Son · 1940 · age 25 · b. ~1915 · Massachusetts
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Sibling
John Mahoney
Sibling · 1940 · age 35
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Henry Mahoney
Sibling · 1940 · age 32
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Mahoney
Sibling · 1940 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Philip Mahoney
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Vincent Mahoney
Sibling · 1940 · age 24
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Stephen Mahoney
Sibling · 1940 · age 33
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Margaret Mahoney
Sibling · 1940 · age 34
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-t0627-01704-00153)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Cecelia Leighton | 22 | Daughter | Office Clerk | Massachusetts |
| 42 | Margaret Cavanaugh | 61 | Head | Dental Nurse | Massachusetts |
| 43 | Maurice E Cavanaugh | 60 | Brother | Lawyer | Massachusetts |
| 44 | Charles Cavanaugh | 56 | Brother | Lawyer | Massachusetts |
| 45 | Dennis Mahoney | 67 | Head | Cooper | Eire |
| 46 | Bridget Mahoney | 63 | Wife | — | Eire |
| 47 | John J Mahoney | 35 | Son | Roofer | Massachusetts |
| 48 | Margaret Mahoney | 34 | Daughter | — | Massachusetts |
| 49 | Stephen Mahoney | 33 | Son | Clerk | Massachusetts |
| 50 | Henry J Mahoney | 32 | Son | Clerk | Massachusetts |
| 51 | James E Mahoney THIS PERSON | 25 | Son | Clerk | Massachusetts |
| 52 | Vincent Mahoney | 24 | Son | — | Massachusetts |
| 53 | Edward Mahoney | 22 | Son | Truck Driver | Massachusetts |
| 54 | Philip Mahoney | 18 | Son | — | Massachusetts |
| 55 | John Ninan | 59 | Head | Civil Engineer | England |
| 56 | Lucy H Ninan | 54 | Wife | — | England |
| 57 | Gladys M Ninan | 26 | Daughter | Radio Tube Maker | Massachusetts |
| 58 | John Jr Ninan | 22 | Son | Maintenance | Massachusetts |
| 59 | Jean Ninan | 19 | Daughter | Clerk | Massachusetts |
| 60 | David Ninan | 12 | Son | — | England |
| 61 | Mabel Harrington | 72 | Head | — | Eire |
| 62 | Catherine Harrington | 51 | Daughter | Clerk | Massachusetts |
| 63 | John C Harrington | 50 | Son | Business Agent | Massachusetts |
| 64 | Mary Rose Harrington | 45 | Daughter | Switchboard Operator | Massachusetts |
| 65 | Joseph Livermore | 65 | Head | Engineer | Massachusetts |
| 66 | Anna Livermore | 55 | Wife | — | Massachusetts |
| 67 | Marguerite Livermore | 24 | Daughter | Salesgirl | Massachusetts |
| 68 | Stephen Livermore | 32 | Son | Hat Salesman | Massachusetts |
| 69 | Richard Livermore | 29 | Son | Traveler | Massachusetts |
| 70 | Blanche Livermore | 21 | Daughter | — | Massachusetts |
| 71 | Mary Molerian | 76 | Head | — | Massachusetts |
| 72 | Herbert Molerian | 49 | Son | — | Massachusetts |
| 73 | Leo Molerian | 44 | Son | Clerk | Massachusetts |
| 74 | Julietta Molerian | 36 | Daughter | — | Massachusetts |
| 75 | Margaret Stedfield | 45 | Lodger | School Teacher | Massachusetts |
| 76 | Julia C Corlis | 62 | Head | — | Massachusetts |
| 77 | Bliss D Corlis | 23 | Son | Laborer | Massachusetts |
| 78 | Howard C Berry | 59 | Head | Machinist | Massachusetts |
| 79 | Julia A Berry | 56 | Wife | — | Massachusetts |
| 80 | Howard W Berry | 36 | Son | Mixer | 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)