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Mary Mcmahon — 1930 US Census Record
Linked across censuses1930 United States Federal Census · Middlesex, Massachusetts
Our Model Tree links this Mary Mcmahon across the 1920 and 1930 US Censuses in Middlesex, Massachusetts (XGBoost, ~Confirmed) — first a daughter (b.~1911), then head of a 10-person household.
Age 19
b. ~1911
Female
Daughter
Born: Massachusetts
Single
1930 Census Record Details
| Census Year | 1930 |
| Location | Middlesex, Massachusetts |
| Surname | McMahon |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 19 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Additional Details | |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Township / Ward | City Of Lowell |
| Est. Birth Year | ~1911 |
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 1930 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Mary Mcmahon | Daughter | — | 19 | ~1911 |
| Anna Mcmahon | Daughter | — | 20 | ~1910 |
| Monica Mcmahon | Daughter | — | 7 | ~1923 |
| Thomas Mcmahon | Head | — | 47 | ~1883 |
| Richard Mcmahon | Son | — | 5 | ~1925 |
| Thomas Mcmahon | Son | — | 15 | ~1915 |
| Frank Mcmahon | Son | — | 11 | ~1919 |
| Joseph Mcmahon | Son | — | 22 | ~1908 |
| Matthew Mcmahon | Son | — | 8 | ~1922 |
| Eva Mcmahon | Spouse | — | 43 | ~1887 |
Census Appearances
1920
Middlesex, Massachusetts
Daughter, age 9
Middlesex, Massachusetts · implied b. ~1911 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 9 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Speaks English | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1930
Middlesex, Massachusetts
Daughter, age 19
Middlesex, Massachusetts · implied b. ~1911 — 10 household members
| Surname | McMahon |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 19 |
| 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 |
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 2 US Census years (1920 and 1930) in Middlesex, Massachusetts, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Mcmahon
Daughter · 1930 · age 19 · b. ~1911 · Massachusetts
★ You are viewing this record
Sibling
Anna Mcmahon
Sibling · 1930 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Thomas Mcmahon
Sibling · 1930 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Frank Mcmahon
Sibling · 1930 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Matthew Mcmahon
Sibling · 1930 · age 8
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Monica Mcmahon
Sibling · 1930 · age 7
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Richard Mcmahon
Sibling · 1930 · age 5
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Mcmahon
Sibling · 1930 · age 22
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
1930 US Federal Census — Middlesex, Massachusetts
Open full size
1930 US Federal Census — Middlesex, Massachusetts
Page Contents
50 people indexed on this census page (ia:1930:massachusettscensus00reel920:1071)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | John Harrigan | 61 | Head | Plumber | England |
| 2 | Charles Goodchild | 52 | Head | Iron Worker | England |
| 3 | Mildred Goodchild | 47 | Wife | — | England |
| 4 | Elizabeth Goodchild | 24 | Daughter | Nurse | Massachusetts |
| 5 | Margaret Goodchild | 21 | Daughter | Nurse | Massachusetts |
| 6 | Axel Lindstrom | 51 | Head | — | Massachusetts |
| 7 | Charles Lindstrom | 57 | Brother | Laborer | Massachusetts |
| 8 | Catherine Russell | 54 | Head | Nurse | Maine |
| 9 | H. John | 24 | Son | Laborer | Massachusetts |
| 10 | Thomas Mcmahon | 47 | Head | Drug Clerk | Massachusetts |
| 11 | Eva Mcmahon | 43 | Wife | — | Massachusetts |
| 12 | Joseph Mcmahon | 22 | Son | Clerk | Massachusetts |
| 13 | Anna Mcmahon | 20 | Daughter | Nurse | Massachusetts |
| 14 | Mary Mcmahon THIS PERSON | 19 | Daughter | — | Massachusetts |
| 15 | Thomas Mcmahon | 15 | Son | — | Massachusetts |
| 16 | Frank Mcmahon | 11 | Son | — | Massachusetts |
| 17 | Matthew Mcmahon | 8 | Son | — | Massachusetts |
| 18 | Monica Mcmahon | 7 | Daughter | — | Massachusetts |
| 19 | Richard Mcmahon | 5 | Son | — | Massachusetts |
| 20 | George Dupont | 36 | Head | Meat Cutter | New York |
| 21 | Hazel Dupont | 33 | Wife | — | New York |
| 22 | Donald Dupont | 8 | Son | — | Massachusetts |
| 23 | Shirley Dupont | 6 | Daughter | — | Massachusetts |
| 24 | William Russell | 56 | Head | Janitor | Wales |
| 25 | Bridget Russell | 57 | Wife | — | Ireland |
| 26 | William Russell | 27 | Son | Clerk | Massachusetts |
| 27 | Harry Russell | 25 | Son | Electrician | Massachusetts |
| 28 | Mary Russell | 23 | Daughter | Stenographer | Massachusetts |
| 29 | Mildred Russell | 21 | Daughter | Bookkeeper | Massachusetts |
| 30 | Raymond Russell | 18 | Son | — | Massachusetts |
| 31 | Edward Russell | 15 | Son | — | Massachusetts |
| 32 | Grace Russell | 12 | Daughter | — | Massachusetts |
| 33 | Edward Mooney | 57 | Boarder | — | Massachusetts |
| 34 | Michael Ryan | 74 | Head | Janitor | Ireland |
| 35 | Ellen Ryan | 73 | Wife | — | Massachusetts |
| 36 | James Ryan | 45 | Son | Iron Worker | Massachusetts |
| 37 | John Ryan | 42 | Son | Machinist | Massachusetts |
| 38 | Clara Green | 68 | Head | — | Massachusetts |
| 39 | Henry Green | 40 | Son | Carpenter | Massachusetts |
| 40 | Maynard Green | 38 | Son | Mechanic | Massachusetts |
| 41 | Arthur Webber | 59 | Head | — | New York |
| 42 | Helen Webber | 58 | Wife | — | New York |
| 43 | Arthur Webber | 31 | Son | Manager | New York |
| 44 | John Dunlap | 48 | Head | Truck Driver | Massachusetts |
| 45 | Alice Dunlap | 43 | Wife | Weaver | Massachusetts |
| 46 | Ruth Dunlap | 16 | Daughter | — | Massachusetts |
| 47 | Mary Dunlap | 15 | Daughter | — | Massachusetts |
| 48 | Alice Dunlap | 13 | Daughter | — | Massachusetts |
| 49 | Catherine Dunlap | 12 | Daughter | — | Massachusetts |
| 50 | Charles Elliott | 35 | Head | Weaver | Massachusetts |
About This Record & Model Tree
This record was independently indexed by YourRoots from the 1930 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)