MM
Margaret Mcmahon — 1940 US Census Record
Model Tree available1940 United States Federal Census · Middlesex-County, Massachusetts
Our Model Tree links this Margaret Mcmahon across the 1920, 1930 and 1940 US Censuses in Middlesex-County, Massachusetts (XGBoost, ~Confirmed), with identified parents Cornelius & Annie — first a daughter (b.~1904), then head of a 2-person household.
Age 36
b. ~1904
Female
Daughter
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Middlesex-County, Massachusetts |
| Surname | McMahon |
| Given Name | Margaret J |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 36 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Malden city |
| 1935 Residence (County) | Middlesex |
| Additional Details | |
| Occupation | Clerk |
| Industry | Oil Co |
| Class of Worker | PW |
| Hours Worked | 36 |
| Income (1939) | 1400 |
| Highest Grade | H 4 |
| 1935 Residence | Same Place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Clerk |
| Township / Ward | Malden City |
| Est. Birth Year | ~1904 |
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.
2 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Margaret | Age | Birth yr |
|---|---|---|---|---|
| Margaret Mcmahon | Daughter | — | 36 | ~1904 |
| Sarah Mcmahon | Head | — | 64 | ~1876 |
Census Appearances
1920
Middlesex, Massachusetts
Daughter, age 15
Middlesex, Massachusetts · implied b. ~1905 — 11 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Margaret |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 15 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Occupation | Packing Room |
| Industry | Thread Mill |
| Class of Worker | W |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1930
Middlesex, Massachusetts
Daughter, age 25
Middlesex, Massachusetts · implied b. ~1905 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Margaret A |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Occupation | Winder |
| Industry | Thread mill |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Middlesex-County, Massachusetts
Daughter, age 36
Middlesex-County, Massachusetts · implied b. ~1904 — 2 household members
| Surname | McMahon |
| Given Name | Margaret J |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 36 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Malden city |
| 1935 Residence (County) | Middlesex |
| Occupation | Clerk |
| Industry | Oil Co |
| Class of Worker | PW |
| Hours Worked | 36 |
| Income (1939) | 1400 |
| 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 Margaret Mcmahon across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Cornelius Mcmahon (~0.92 confidence) and mother Annie Mcmahon (~0.92 confidence) and mother Margaret Mcmahon (~0.92 confidence) and mother Sarah Mcmahon (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Cornelius Mcmahon
b. ~1878
Source father
● Household
· direct · ~0.92
Mother
Annie Mcmahon
b. ~1880
Source mother
● Household
· direct · ~0.92
Mother
Margaret Mcmahon
b. ~1878
Source mother
● Household
· direct · ~0.92
Mother
Sarah Mcmahon
b. ~1876
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Margaret Mcmahon
Daughter · 1940 · age 36 · b. ~1904 · Massachusetts
★ You are viewing this record
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-t0627-01608-00082)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Henry R Tobler | 45 | Head | Machinist | Massachusetts |
| 42 | Mary Tobler | 41 | Wife | — | Massachusetts |
| 43 | Mary Tobler | 14 | Daughter | — | Massachusetts |
| 44 | Arthur Tobler | 10 | Son | — | Massachusetts |
| 45 | Jean Tobler | 8 | Daughter | — | Massachusetts |
| 46 | Patricia Tobler | 3 | Daughter | — | Massachusetts |
| 47 | Sarah T Roche | 45 | Lodger | Shoe Maker | Eire |
| 48 | Arthur B Maguire | 56 | Head | Clerk | Massachusetts |
| 49 | Olinda R Maguire | 24 | Daughter | Clerk | Maine |
| 50 | Sarah Mcmahon | 64 | Head | — | Eire |
| 51 | Margaret J Mcmahon THIS PERSON | 36 | Daughter | Clerk | Massachusetts |
| 52 | Adelaide Adams | 71 | Head | — | Canada Fr |
| 53 | Mary V Adams | 47 | Daughter | Proprietor | Canada Fr |
| 54 | Joseph Z Adams | 25 | Son | Laborer | Canada Fr |
| 55 | Donald E Mcintyre | 35 | Head | Production Man | Massachusetts |
| 56 | Viola R Mcintyre | 37 | Sister | — | Massachusetts |
| 57 | Clara T Mcintyre | 74 | Mother | — | England |
| 58 | Ira D Thomas | 55 | Head | — | New Hampshire |
| 59 | Dorothy Thomas | 27 | Daughter | Secretary | Massachusetts |
| 60 | Mary M Mckeon | 58 | Lodger | — | Massachusetts |
| 61 | Willie C Hasson | 34 | Head | Hoisting Eng'R | Canada Eng |
| 62 | M Kathleen Hasson | 36 | Wife | — | Canada Eng |
| 63 | Kathleen J Hasson | 6 | Daughter | — | Massachusetts |
| 64 | Robert F D Hasson | 0 | Son | — | Massachusetts |
| 65 | John J Fowler | 46 | Head | Newspaper Press Foreman | Massachusetts |
| 66 | Mary W Fowler | 47 | Wife | — | Pennsylvania |
| 67 | John P Fowler | 15 | Son | — | Massachusetts |
| 68 | Frank T Walle | 53 | Head | Salesman | Massachusetts |
| 69 | Joseph T Walle | 52 | Brother | Driver | Massachusetts |
| 70 | William J Walle | 43 | Brother | Laborer | Massachusetts |
| 71 | Albert C Walle | 40 | Brother | Laborer | Massachusetts |
| 72 | Alice M Walle | 57 | Sister | — | Massachusetts |
| 73 | Francis L Coholan | 25 | Head | Salesman | Massachusetts |
| 74 | Emily S Coholan | 27 | Wife | — | Massachusetts |
| 75 | Leslie Coholan | 7 | Son | — | Massachusetts |
| 76 | Donald Coholan | 3 | Son | — | Massachusetts |
| 77 | Sarah F Poole | 60 | Mother In Law | — | Massachusetts |
| 78 | James R Enos | 24 | Head | Proprietor | Massachusetts |
| 79 | Margaret D Enos | 22 | Wife | — | Massachusetts |
| 80 | James R Jr Enos | 2 | Son | — | Massachusetts |
Pedigree Summary
Margaret
Gen 1 · 4 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)