MD
Mary Duffy — 1930 US Census Record
Linked across censuses1930 United States Federal Census · Philadelphia, Pennsylvania
Our Model Tree links this Mary Duffy across the 1920 and 1930 US Censuses in Philadelphia, Pennsylvania (XGBoost, ~Confirmed) — first a daughter (b.~1905), then head of a 14-person household.
Age 25
b. ~1905
Female
Daughter
Born: Pennsylvania
Single
1930 Census Record Details
| Census Year | 1930 |
| Location | Philadelphia, Pennsylvania |
| Surname | Duffy |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Additional Details | |
| Can Read/Write | Yes |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
| Township / Ward | Philadelphia City |
| Est. Birth Year | ~1905 |
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.
14 people recorded at the same address in the 1930 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Theresa Duffy | Daughter | — | 10 | ~1920 |
| Catherine Duffy | Daughter | — | 22 | ~1908 |
| Rita Duffy | Daughter | — | 8 | ~1922 |
| Anna Duffy | Daughter | — | 6 | ~1924 |
| Elizabeth Duffy | Daughter | — | 12 | ~1918 |
| Mary Duffy | Daughter | — | 25 | ~1905 |
| John Duffy | Head | — | 50 | ~1880 |
| Francis Duffy | Son | — | 16 | ~1914 |
| Joseph Duffy | Son | — | 18 | ~1912 |
| William Duffy | Son | — | 4 | ~1926 |
| John Duffy | Son | — | 20 | ~1910 |
| James Duffy | Son | — | 14 | ~1916 |
| Robert Duffy | Son | — | 2 | ~1928 |
| Mary Duffy | Spouse | — | 50 | ~1880 |
Census Appearances
1920
Philadelphia, Pennsylvania
Daughter, age 14
Philadelphia, Pennsylvania · implied b. ~1906 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | Mary E |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1930
Philadelphia, Pennsylvania
Daughter, age 25
Philadelphia, Pennsylvania · implied b. ~1905 — 14 household members
| Surname | Duffy |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Can Read/Write | Yes |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
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 Duffy across 2 US Census years (1920 and 1930) in Philadelphia, Pennsylvania, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Duffy
Daughter · 1930 · age 25 · b. ~1905 · Pennsylvania
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Sibling
James Duffy
Sibling · 1930 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Duffy
Sibling · 1930 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Catherine Duffy
Sibling · 1930 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Elizabeth Duffy
Sibling · 1930 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
William Duffy
Sibling · 1930 · age 4
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Rita Duffy
Sibling · 1930 · age 8
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Robert Duffy
Sibling · 1930 · age 2
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Duffy
Sibling · 1930 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Francis Duffy
Sibling · 1930 · age 16
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Theresa Duffy
Sibling · 1930 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Anna Duffy
Sibling · 1930 · age 6
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 — Philadelphia, Pennsylvania
Open full size
1930 US Federal Census — Philadelphia, Pennsylvania
Page Contents
50 people indexed on this census page (ia:1930:fifteenthcensus00reel2126:0726)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 51 | Walter Hughes | 45 | Head | Machinist | England |
| 52 | Nellie Hughes | 47 | Wife | — | Pennsylvania |
| 53 | Catherine Byron | 27 | Daughter | Clerk | Pennsylvania |
| 54 | George Byron | 20 | Son | Clerk | Pennsylvania |
| 55 | Joseph Hughes | 18 | Son | Clerk | Pennsylvania |
| 56 | Mary Muldowney | 75 | Mother-in-law | — | Pennsylvania |
| 57 | Andrew Tucker | 51 | Head | — | Pennsylvania |
| 58 | Elizabeth Tucker | 48 | Wife | — | Pennsylvania |
| 59 | Eugene Tucker | 20 | Son | Clerk | Pennsylvania |
| 60 | Elizabeth Tucker | 18 | Daughter | — | Pennsylvania |
| 61 | Andrew Tucker | 16 | Son | — | Pennsylvania |
| 62 | Madeline Tucker | 14 | Daughter | — | Pennsylvania |
| 63 | Frank Heilman | 47 | Head | — | Pennsylvania |
| 64 | Mary Heilman | 45 | Wife | — | Pennsylvania |
| 65 | Frank Heilman | 18 | Son | — | Pennsylvania |
| 66 | Joseph Heilman | 16 | Son | — | Pennsylvania |
| 67 | Raymond Schmidt | 32 | Head | Clerk | Pennsylvania |
| 68 | Mary Schmidt | 32 | Wife | — | Pennsylvania |
| 69 | Raymond Schmidt | 5 | Son | — | Pennsylvania |
| 70 | John Duffy | 50 | Head | — | Pennsylvania |
| 71 | Mary Duffy | 50 | Wife | — | Pennsylvania |
| 72 | Mary Duffy THIS PERSON | 25 | Daughter | — | Pennsylvania |
| 73 | Catherine Duffy | 22 | Daughter | — | Pennsylvania |
| 74 | John Duffy | 20 | Son | — | Pennsylvania |
| 75 | Joseph Duffy | 18 | Son | — | Pennsylvania |
| 76 | Francis Duffy | 16 | Son | — | Pennsylvania |
| 77 | James Duffy | 14 | Son | — | Pennsylvania |
| 78 | Elizabeth Duffy | 12 | Daughter | — | Pennsylvania |
| 79 | Theresa Duffy | 10 | Daughter | — | Pennsylvania |
| 80 | Rita Duffy | 8 | Daughter | — | Pennsylvania |
| 81 | Anna Duffy | 6 | Daughter | — | Pennsylvania |
| 82 | William Duffy | 4 | Son | — | Pennsylvania |
| 83 | Robert Duffy | 2 | Son | — | Pennsylvania |
| 84 | William J. Duffy | 41 | Head | — | Pennsylvania |
| 85 | Elizabeth Duffy | 40 | Wife | — | Pennsylvania |
| 86 | William Duffy | 14 | Son | — | Pennsylvania |
| 87 | Elizabeth Duffy | 12 | Daughter | — | Pennsylvania |
| 88 | John Duffy | 10 | Son | — | Pennsylvania |
| 89 | Helen Duffy | 8 | Daughter | — | Pennsylvania |
| 90 | Irene M. Duffy | 6 | Daughter | — | Pennsylvania |
| 91 | Anna E. Duffy | 4 | Daughter | — | Pennsylvania |
| 92 | William J. Duffy | 2 | Son | — | Pennsylvania |
| 93 | Ruth Laughlin | 21 | Daughter | — | Pennsylvania |
| 94 | Arthur Thomas | 23 | Head | — | Pennsylvania |
| 95 | Helen Thomas | 23 | Wife | — | Pennsylvania |
| 96 | William Thomas | 3 | Son | — | Pennsylvania |
| 97 | Elizabeth Thomas | 1 | Daughter | — | Pennsylvania |
| 98 | Arthur Thomas | 0 | Son | — | Pennsylvania |
| 99 | Elizabeth Gardner | 27 | Sister | — | Pennsylvania |
| 100 | Benjamin Messman | 52 | Head | Tailor | Russia |
Related Census Records
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)