WM
William Mcmahon — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Suffolk-County, Massachusetts
Our Model Tree links this William Mcmahon across the 1930 and 1940 US Censuses in Suffolk-County, Massachusetts (XGBoost, ~Confirmed) — first a son (b.~1913), then head of a 7-person household.
Age 27
b. ~1913
Male
Son
Born: Scotland
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Suffolk-County, Massachusetts |
| Surname | McMahon |
| Given Name | William J. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Single |
| Birthplace | Scotland |
| 1935 Residence (City) | Boston |
| 1935 Residence (County) | Suffolk |
| Naturalization Status | Alien |
| Additional Details | |
| Hours Worked | 60 |
| Income (1939) | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth Country | Scotland |
| Birthplace (normalized) | scotland |
| Township / Ward | Boston |
| Est. Birth Year | ~1913 |
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.
7 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to William | Age | Birth yr |
|---|---|---|---|---|
| Christina Mcmahon | Daughter | — | 20 | ~1920 |
| Elizabeth Mcmahon | Spouse | — | 49 | ~1891 |
| Patricia Mcmahon | Daughter | — | 17 | ~1923 |
| John Mcmahon | Head | — | 51 | ~1889 |
| William Mcmahon | Son | — | 27 | ~1913 |
| Mary Mcmahon | Daughter | — | 12 | ~1928 |
| John Mcmahon | Son | — | 28 | ~1912 |
Census Appearances
1930
Suffolk, Massachusetts
Son, age 16
Suffolk, Massachusetts · implied b. ~1914 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | William |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 16 |
| Marital Status | Single |
| Birthplace | Scotland |
| Naturalization Status | Naturalized |
| Year of Immigration | 1922 |
| Father's Birthplace | Scotland |
| Mother's Birthplace | Scotland |
| Occupation | Helper |
| Industry | Garage |
| Class of Worker | W |
| Can Read/Write | Yes |
| Mother Tongue | English |
| Birth Country | Scotland |
| Birthplace (normalized) | scotland |
1940
Suffolk-County, Massachusetts
Son, age 27
Suffolk-County, Massachusetts · implied b. ~1913 — 7 household members
| Surname | McMahon |
| Given Name | William J. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Single |
| Birthplace | Scotland |
| 1935 Residence (City) | Boston |
| 1935 Residence (County) | Suffolk |
| Naturalization Status | Alien |
| Hours Worked | 60 |
| Income (1939) | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth Country | Scotland |
| Birthplace (normalized) | scotland |
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 William Mcmahon across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
William Mcmahon
Son · 1940 · age 27 · b. ~1913 · Massachusetts
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Sibling
Mary Mcmahon
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Patricia Mcmahon
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Mcmahon
Sibling · 1940 · age 28
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Christina Mcmahon
Sibling · 1940 · age 20
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 — Suffolk-County, Massachusetts
Open full size
1940 US Federal Census — Suffolk-County, Massachusetts
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01672-00328)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Rena Rabatsky | 10 | Daughter | — | Massachusetts |
| 2 | Charles Rabatsky | 5 | Son | — | Massachusetts |
| 3 | Marlene Rabatsky | 2 | Daughter | — | Massachusetts |
| 4 | William Locke | 42 | Head | Insurance Agent | Massachusetts |
| 5 | Frances Locke | 40 | Wife | — | Massachusetts |
| 6 | Cecile Locke | 19 | Daughter | — | Massachusetts |
| 7 | Marilyn Locke | 5 | Daughter | — | Massachusetts |
| 8 | John Mcmahon | 51 | Head | Janitor | Scotland |
| 9 | Elizabeth Mcmahon | 49 | Wife | — | Scotland |
| 10 | John Mcmahon | 28 | Son | Salesman | Scotland |
| 11 | William J. Mcmahon THIS PERSON | 27 | Son | — | Scotland |
| 12 | Christina Mcmahon | 20 | Daughter | — | Scotland |
| 13 | Patricia Mcmahon | 17 | Daughter | — | Massachusetts |
| 14 | Mary Mcmahon | 12 | Daughter | — | Massachusetts |
| 15 | — | None | — | — | — |
| 16 | James L. Riley | 64 | Head | Tailor | Canada Eng |
| 17 | Fannie Yuretsky | 69 | Head | — | Hungary |
| 18 | Cyrus J. Young | 28 | Son | Chauffeur | Massachusetts |
| 19 | Isabelle Thompson | 43 | Head | Practical Nurse | Massachusetts |
| 20 | Isabelle Thompson | 13 | Daughter | — | Massachusetts |
| 21 | Leonard Del Signore | 76 | Head | Stitcher | Italy |
| 22 | Frances Del Signore | 65 | Wife | — | Italy |
| 23 | Ann Riley | 78 | Head | — | Free State |
| 24 | Elizabeth Riley | 55 | Daughter | — | Massachusetts |
| 25 | Zina Clark | 71 | Head | — | Massachusetts |
| 26 | Irving Clark | 28 | Son | Laborer | Massachusetts |
| 27 | Esther Lapidas | 51 | Head | — | Russia |
| 28 | Meriam Lapidas | 17 | Daughter | New Worker | Massachusetts |
| 29 | Gene Lapidas | 15 | Daughter | — | Massachusetts |
| 30 | Dominick La Perla | 35 | Head | Peddler, Fruit | Italy |
| 31 | Thomas J. Sr. Halloran | 70 | Head | — | Irish Free State |
| 32 | Thomas J. Jr. Halloran | 34 | Son | Mail Carrier | Massachusetts |
| 33 | Frank Deagan | 36 | Lodger | Mail Carrier | Maine |
| 34 | John F. Zender | 39 | Head | Painter | Massachusetts |
| 35 | Violet Zender | 34 | Wife | — | Massachusetts |
| 36 | Helen Zender | 12 | Daughter | — | Massachusetts |
| 37 | William Zender | 11 | Son | — | Massachusetts |
| 38 | Hobart Dingee | 68 | Head | Watchman | Canada English |
| 39 | Frances Dingee | 65 | Wife | — | Canada English |
| 40 | John Dingee | 39 | Son | Handy Man | Canada English |
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)