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Mary Mcmahon — 1940 US Census Record
Model Tree available1940 United States Federal Census · Essex-County, Massachusetts
Our Model Tree links this Mary Mcmahon across the 1920, 1930 and 1940 US Censuses in Essex-County, Massachusetts (XGBoost, ~Confirmed), with identified parents James & James — first a daughter (b.~1917), then head of a 9-person household.
Age 23
b. ~1917
Female
Daughter
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Essex-County, Massachusetts |
| Surname | McMahon |
| Given Name | Mary R. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | BEVERLY CITY |
| 1935 Residence (County) | ESSEX |
| Additional Details | |
| Occupation | Saleslady |
| Industry | Retail Store |
| Class of Worker | PW |
| Hours Worked | 8 |
| Income (1939) | 60 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Saleslady |
| Township / Ward | Beverly City |
| Est. Birth Year | ~1917 |
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 Mary | Age | Birth yr |
|---|---|---|---|---|
| Helena Mcmahon | Daughter | — | 33 | ~1907 |
| Alice Mcmahon | Daughter | — | 29 | ~1911 |
| Loretta Mcmahon | Daughter | — | 26 | ~1914 |
| Mary Mcmahon | Daughter | — | 23 | ~1917 |
| James Mcmahon | Head | — | 67 | ~1873 |
| Mary Mcmahon | Other | — | 73 | ~1867 |
| Charles Mcmahon | Son | — | 33 | ~1907 |
| James Mcmahon | Son | — | 38 | ~1902 |
| Helena Mcmahon | Spouse | — | 58 | ~1882 |
Census Appearances
1920
Essex, Massachusetts
Daughter, age 2
Essex, Massachusetts · implied b. ~1918 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Mary R |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 2 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Can Read | No |
| Can Write | No |
| Speaks English | No |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1930
Essex, Massachusetts
Daughter, age 13
Essex, Massachusetts · implied b. ~1917 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Mary A. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Essex-County, Massachusetts
Daughter, age 23
Essex-County, Massachusetts · implied b. ~1917 — 9 household members
| Surname | McMahon |
| Given Name | Mary R. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 23 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | BEVERLY CITY |
| 1935 Residence (County) | ESSEX |
| Occupation | Saleslady |
| Industry | Retail Store |
| Class of Worker | PW |
| Hours Worked | 8 |
| Income (1939) | 60 |
| 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 Mary Mcmahon across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father James Mcmahon (~0.92 confidence) and father James Mcmahon (~0.92 confidence) and father James Mcmahon (~0.92 confidence) and mother Helena Mcmahon (~0.92 confidence) and mother Helena Mcmahon (~0.92 confidence). The pedigree spans 1 generation with 5 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
James Mcmahon
b. ~1872
Source father
● Household
· direct · ~0.92
Father
James Mcmahon
b. ~1873
Source father
● Household
· direct · ~0.92
Father
James Mcmahon
b. ~1877
Source father
● Household
· direct · ~0.92
Mother
Helena Mcmahon
b. ~1881
Source mother
● Household
· direct · ~0.92
Mother
Helena Mcmahon
b. ~1882
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Mary Mcmahon
Daughter · 1940 · age 23 · b. ~1917 · Massachusetts
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Sibling
Alice Mcmahon
Sibling · 1940 · age 29
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Helena Mcmahon
Sibling · 1940 · age 33
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Loretta Mcmahon
Sibling · 1940 · age 26
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Charles Mcmahon
Sibling · 1940 · age 33
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
James Mcmahon
Sibling · 1940 · age 38
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 — Essex-County, Massachusetts
Open full size
1940 US Federal Census — Essex-County, Massachusetts
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01577-00775)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Alice O. Howard | 44 | Head | Machine Operator | New Hampshire |
| 42 | Lawrence R. Howard | 23 | Son | Radio Announcer | New Hampshire |
| 43 | William L. Howard | 16 | Son | — | New Hampshire |
| 44 | Juliet Botsvert | 31 | Sister | Laundress | New Hampshire |
| 45 | Latishia Manthorne | 62 | Head | — | Nova Scotia |
| 46 | Anna M. Manthorne | 41 | Daughter | Hairdresser | Massachusetts |
| 47 | Annie M. Blenkhorn | 64 | Sister | Housekeeper | Nova Scotia |
| 48 | Joseph Jacques | 53 | Head | Molder | French Canadian |
| 49 | Orelia Jacques | 56 | Wife | — | French Canadian |
| 50 | Lena G. Jacques | 29 | Daughter | Clerk | Massachusetts |
| 51 | William Jacques | 27 | Son | Machinist | Massachusetts |
| 52 | Lucy Jacques | 17 | Daughter | Clerk | Massachusetts |
| 53 | Louis Jacques | 14 | Son | — | Massachusetts |
| 54 | Theresa Jacques | 11 | Daughter | — | Massachusetts |
| 55 | John B. Jr. Larivee | 45 | Head | Machinist | Massachusetts |
| 56 | Josephine Larivee | 43 | Wife | — | Massachusetts |
| 57 | John J. Larivee | 16 | Son | — | Massachusetts |
| 58 | Robert J. Larivee | 15 | Son | — | Massachusetts |
| 59 | Elizabeth J. Larivee | 13 | Daughter | — | Massachusetts |
| 60 | James E. Mcmahon | 67 | Head | Machinist | Massachusetts |
| 61 | Helena V. Mcmahon | 58 | Wife | — | Massachusetts |
| 62 | James E. Jr. Mcmahon | 38 | Son | Machinist | Massachusetts |
| 63 | Charles H. Mcmahon | 33 | Son | Salesman | Massachusetts |
| 64 | Helena V. Mcmahon | 33 | Daughter | Housekeeper | Massachusetts |
| 65 | Alice F. Mcmahon | 29 | Daughter | Clerk | Massachusetts |
| 66 | Loretta A. Mcmahon | 26 | Daughter | Stenographer | Massachusetts |
| 67 | Mary R. Mcmahon THIS PERSON | 23 | Daughter | Saleslady | Massachusetts |
| 68 | Mary A. Mcmahon | 73 | Sister | — | Massachusetts |
| 69 | Victor A. Townsend | 54 | Head | — | England |
| 70 | Ruth Townsend | 48 | Wife | — | England |
| 71 | Benjamin Townsend | 23 | Son | Welder | Massachusetts |
| 72 | Herbert J. Townsend | 22 | Son | Gardner | Massachusetts |
| 73 | Ruth Jones | 23 | Daughter in law | — | England |
| 74 | Luther Sr. Franks | 54 | Head | Tool Engineer | Massachusetts |
| 75 | Elizabeth M. Franks | 53 | Wife | — | Massachusetts |
| 76 | Dudley E. Smith | 57 | Head | Wood Worker | Quebec |
| 77 | Mary A. Smith | 54 | Wife | — | Quebec |
| 78 | Jane L. Simmicks | 72 | Sister in law | — | Quebec |
| 79 | Arthur J. Buckley | 46 | Head | Wood Worker | Massachusetts |
| 80 | Mary H. Buckley | 46 | Wife | — | Massachusetts |
Pedigree Summary
Mary + 5 siblings
Gen 1 · 5 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)