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John Mcmahon — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Suffolk-County, Massachusetts
Our Model Tree links this John Mcmahon across the 1930 and 1940 US Censuses in Suffolk-County, Massachusetts (XGBoost, ~Confirmed) — first a son (b.~1916), then head of a 10-person household.
Age 24
b. ~1916
Male
Son
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Suffolk-County, Massachusetts |
| Surname | McMahon |
| Given Name | John M. |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 24 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Boston City |
| 1935 Residence (County) | Suffolk |
| Additional Details | |
| Occupation | retail grocery meat clerk |
| Industry | chain meat market |
| Class of Worker | PW |
| Hours Worked | 53 |
| Income (1939) | 1040 |
| Highest Grade | C 2 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Retail Grocery Meat Clerk |
| Township / Ward | Boston City |
| Est. Birth Year | ~1916 |
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 John | Age | Birth yr |
|---|---|---|---|---|
| Ann Mcmahon | Daughter | — | 17 | ~1923 |
| Dorothy Mcmahon | Daughter | — | 22 | ~1918 |
| Claire Mcmahon | Daughter | — | 19 | ~1921 |
| James Mcmahon | Head | — | 59 | ~1881 |
| Kevin Mcmahon | Son | — | 10 | ~1930 |
| James Mcmahon | Son | — | 27 | ~1913 |
| Cornelius Mcmahon | Son | — | 15 | ~1925 |
| Joseph Mcmahon | Son | — | 13 | ~1927 |
| John Mcmahon | Son | — | 24 | ~1916 |
| Mary Mcmahon | Spouse | — | 52 | ~1888 |
Census Appearances
1930
Suffolk, Massachusetts
Other, age 13
Suffolk, Massachusetts · implied b. ~1917 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | MacMahon |
| Given Name | John A. |
| Relationship to Head | Lodger |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | New York |
| Mother's Birthplace | Massachusetts |
| Occupation | Scholar |
| Can Read/Write | Yes |
| Veteran | No |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Suffolk-County, Massachusetts
Son, age 24
Suffolk-County, Massachusetts · implied b. ~1916 — 10 household members
| Surname | McMahon |
| Given Name | John M. |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 24 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Boston City |
| 1935 Residence (County) | Suffolk |
| Occupation | retail grocery meat clerk |
| Industry | chain meat market |
| Class of Worker | PW |
| Hours Worked | 53 |
| Income (1939) | 1040 |
| Highest Grade | C 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 John Mcmahon across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Mcmahon
Son · 1940 · age 24 · b. ~1916 · Massachusetts
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Sibling
Joseph Mcmahon
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Dorothy Mcmahon
Sibling · 1940 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
James Mcmahon
Sibling · 1940 · age 27
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Kevin Mcmahon
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Ann Mcmahon
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Claire Mcmahon
Sibling · 1940 · age 19
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Cornelius Mcmahon
Sibling · 1940 · age 15
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-t0627-01682-00831)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Glenna Clarke | 33 | wife | — | Canada-English |
| 2 | Charles R. Clarke | 11 | son | — | Massachusetts |
| 3 | Harry E. Jr. Clarke | 9 | son | — | Massachusetts |
| 4 | Muriel I. Clarke | 7 | daughter | — | Massachusetts |
| 5 | Mary E. Clarke | 3 | daughter | — | Massachusetts |
| 6 | Gordon W. Clarke | 1 | son | — | Massachusetts |
| 7 | Charles Wheeler | 28 | lodger | Fruit And Vegetable Peddler | Maine |
| 8 | Patrick J. Brady | 39 | head | Cook | North of Ireland |
| 9 | Rose Brady | 44 | wife | — | North of Ireland |
| 10 | Bridget Brady | 16 | daughter | — | North of Ireland |
| 11 | Rose A. Brady | 12 | daughter | — | North of Ireland |
| 12 | Patrick J. Jr. Brady | 5 | son | — | Massachusetts |
| 13 | Mary C. Brady | 2 | neice | — | Massachusetts |
| 14 | Costanzo Cellucci | 44 | head | Paver | Italy |
| 15 | Lucy Cellucci | 21 | daughter | House Keeper | Massachusetts |
| 16 | Maria Cellucci | 18 | daughter | House Keeper | Massachusetts |
| 17 | Domenica Cellucci | 16 | daughter | — | Massachusetts |
| 18 | Rosie Cellucci | 15 | daughter | — | Massachusetts |
| 19 | Thomas Cellucci | 12 | son | — | Massachusetts |
| 20 | Emily Cellucci | 10 | daughter | — | Massachusetts |
| 21 | James B. Mcmahon | 59 | head | Blacksmith | New York |
| 22 | Mary Mcmahon | 52 | wife | — | New York |
| 23 | James G. Mcmahon | 27 | son | Store Manager | Massachusetts |
| 24 | John M. Mcmahon THIS PERSON | 24 | son | Retail Grocery Meat Clerk | Massachusetts |
| 25 | Dorothy T. Mcmahon | 22 | daughter | Graduate Attendant Nurse | Massachusetts |
| 26 | Claire Mcmahon | 19 | daughter | — | Massachusetts |
| 27 | Ann Louise Mcmahon | 17 | daughter | — | Massachusetts |
| 28 | Cornelius Mcmahon | 15 | son | — | Massachusetts |
| 29 | Joseph V. Mcmahon | 13 | son | — | Massachusetts |
| 30 | Kevin Mcmahon | 10 | son | — | Massachusetts |
| 31 | Alice E. Coughlin | 52 | head | Waitress | Massachusetts |
| 32 | Margaret Crean | 70 | head | — | New York |
| 33 | Elizabeth M. Crean | 33 | daughter | Stenographer | Massachusetts |
| 34 | Margaret L. Crean | 31 | daughter | Stenographer | Massachusetts |
| 35 | Mary B. Crean | 29 | daughter | — | Massachusetts |
| 36 | Rocco J. Sammartano | 30 | head | Master Plumber | Italy |
| 37 | Margaret I. Sammartano | 28 | wife | — | Massachusetts |
| 38 | Ann M. Sammartano | 2 | daughter | — | Massachusetts |
| 39 | Patrick W. Brogie | 61 | head | Laborer | Massachusetts |
| 40 | Mary E. Brogie | 59 | sister | — | 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)