MC
Mary Cassidy — 1930 US Census Record
Linked across censuses1930 United States Federal Census · Middlesex, Massachusetts
Our Model Tree links this Mary Cassidy across the 1920 and 1930 US Censuses in Middlesex, Massachusetts (XGBoost, ~Confirmed) — first a daughter (b.~1910), then head of a 10-person household.
Age 20
b. ~1910
Female
Daughter
Born: Massachusetts
Single
1930 Census Record Details
| Census Year | 1930 |
| Location | Middlesex, Massachusetts |
| Surname | Cassidy |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 20 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Additional Details | |
| Occupation | Clerk |
| Industry | Dept. Store |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Clerk |
| Township / Ward | City Of Cambridge |
| Est. Birth Year | ~1910 |
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 |
|---|---|---|---|---|
| Rita Cassidy | Daughter | — | 5 | ~1925 |
| Mary Cassidy | Daughter | — | 20 | ~1910 |
| Catherine Cassidy | Daughter | — | 13 | ~1917 |
| James Cassidy | Head | — | 45 | ~1885 |
| John Cassidy | Son | — | 11 | ~1919 |
| Thomas Cassidy | Son | — | 18 | ~1912 |
| James Cassidy | Son | — | 22 | ~1908 |
| Paul Cassidy | Son | — | 8 | ~1922 |
| Joseph Cassidy | Son | — | 6 | ~1924 |
| Julia Cassidy | Spouse | — | 45 | ~1885 |
Census Appearances
1920
Middlesex, Massachusetts
Other, age 9
Middlesex, Massachusetts · implied b. ~1911 — 50 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Cassidy |
| Given Name | Mary |
| Relationship to Head | Boarder |
| Sex | F |
| Color / Race | White |
| Age | 9 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Occupation | Student |
| Industry | St Peters Orphanage |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | English |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1930
Middlesex, Massachusetts
Daughter, age 20
Middlesex, Massachusetts · implied b. ~1910 — 10 household members
| Surname | Cassidy |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 20 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Occupation | Clerk |
| Industry | Dept. Store |
| Class of Worker | W |
| 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 Cassidy across 2 US Census years (1920 and 1930) in Middlesex, Massachusetts, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Cassidy
Daughter · 1930 · age 20 · b. ~1910 · Massachusetts
★ You are viewing this record
Sibling
John Cassidy
Sibling · 1930 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Thomas Cassidy
Sibling · 1930 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Cassidy
Sibling · 1930 · age 6
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
James Cassidy
Sibling · 1930 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Paul Cassidy
Sibling · 1930 · age 8
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Rita Cassidy
Sibling · 1930 · age 5
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Catherine Cassidy
Sibling · 1930 · age 13
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:1930:15thcensuspopula917unit:0430)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Howard Russell | 38 | Head | Chauffeur | Massachusetts |
| 2 | Eva Russell | 38 | Wife | — | Massachusetts |
| 3 | Howard Russell | 15 | Son | — | Massachusetts |
| 4 | Edith Russell | 9 | Daughter | — | Massachusetts |
| 5 | Robert Russell | 8 | Son | — | Massachusetts |
| 6 | Joseph Russell | 6 | Son | — | Massachusetts |
| 7 | Arthur Russell | 5 | Son | — | Massachusetts |
| 8 | Francis Russell | 3 | Son | — | Massachusetts |
| 9 | James Cassidy | 45 | Head | Laborer | Massachusetts |
| 10 | Julia Cassidy | 45 | Wife | — | Massachusetts |
| 11 | James Cassidy | 22 | Son | Laborer | Massachusetts |
| 12 | Mary Cassidy THIS PERSON | 20 | Daughter | Clerk | Massachusetts |
| 13 | Thomas Cassidy | 18 | Son | — | Massachusetts |
| 14 | Catherine Cassidy | 13 | Daughter | — | Massachusetts |
| 15 | John Cassidy | 11 | Son | — | Massachusetts |
| 16 | Paul Cassidy | 8 | Son | — | Massachusetts |
| 17 | Joseph Cassidy | 6 | Son | — | Massachusetts |
| 18 | Rita Cassidy | 5 | Daughter | — | Massachusetts |
| 19 | Patrick Sullivan | 37 | Head | Conductor | Ireland |
| 20 | Mary Sullivan | 37 | Wife | — | Ireland |
| 21 | Paul Sullivan | 10 | Son | — | Massachusetts |
| 22 | Arthur Sullivan | 5 | Son | — | Massachusetts |
| 23 | John Fitzpatrick | 32 | Head | Iron Worker | Massachusetts |
| 24 | Mary Fitzpatrick | 32 | Wife | — | Massachusetts |
| 25 | Mary Fitzpatrick | 2 | Daughter | — | Massachusetts |
| 26 | John O'Brien | 28 | Head | Iron Worker | Massachusetts |
| 27 | Julia O'Brien | 25 | Wife | Stitcher | Massachusetts |
| 28 | John O'Brien | 1 | Son | — | Massachusetts |
| 29 | Mary O'Brien | 0 | Daughter | — | Massachusetts |
| 30 | Morris Rabin | 40 | Head | Painter | Russia |
| 31 | Rose Rabin | 34 | Wife | — | Russia |
| 32 | Samuel Rabin | 13 | Son | — | Massachusetts |
| 33 | Gertrude Rabin | 11 | Daughter | — | Massachusetts |
| 34 | Harold Rabin | 10 | Son | — | Massachusetts |
| 35 | Patrick Walsh | 35 | Head | Laborer | Massachusetts |
| 36 | Mary Walsh | 37 | Wife | — | Massachusetts |
| 37 | Patrick Walsh | 7 | Son | — | Massachusetts |
| 38 | James Walsh | 5 | Son | — | Massachusetts |
| 39 | Raymond Walsh | 3 | Son | — | Massachusetts |
| 40 | Thomas Walsh | 1 | Son | — | Massachusetts |
| 41 | Daniel Donovan | 30 | Head | Laborer | Massachusetts |
| 42 | Delia Donovan | 26 | Wife | — | Massachusetts |
| 43 | Beatrice Donovan | 1 | Daughter | — | Massachusetts |
| 44 | James Decourcy | 40 | Head | Laborer | Massachusetts |
| 45 | Julia Decourcy | 38 | Wife | — | Massachusetts |
| 46 | James Decourcy | 14 | Son | — | Massachusetts |
| 47 | John Decourcy | 12 | Son | — | Massachusetts |
| 48 | Francis Decourcy | 10 | Son | — | Massachusetts |
| 49 | William Decourcy | 8 | Son | — | Massachusetts |
| 50 | Paul Decourcy | 6 | Son | — | 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)