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Mary Mcdermott — 1940 US Census Record
Model Tree available1940 United States Federal Census · Philadelphia-County, Pennsylvania
Our Model Tree links this Mary Mcdermott across the 1920, 1930 and 1940 US Censuses in Philadelphia-County, Pennsylvania (XGBoost, ~Confirmed), with identified parents William & Elizabeth — first a daughter (b.~1919), then head of a 5-person household.
Age 21
b. ~1919
Female
Daughter
Born: Pennsylvania
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Philadelphia-County, Pennsylvania |
| Surname | McDermott |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | Ardmore |
| 1935 Residence (County) | Montg Co |
| Additional Details | |
| Occupation | File Clerk |
| Industry | Hospital |
| Class of Worker | PW |
| Hours Worked | 0 |
| Income (1939) | 240 |
| Highest Grade | Hs 1 |
| 1935 Residence | Pennsylvania |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
| Occupation | File Clerk |
| Township / Ward | Philadelphia |
| Est. Birth Year | ~1919 |
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.
5 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Mary Mcdermott | Daughter | — | 21 | ~1919 |
| Martin Mcdermott | Head | — | 50 | ~1890 |
| Edward Mcdermott | Son | — | 20 | ~1920 |
| Martin Mcdermott | Son | — | 17 | ~1923 |
| Elizabeth Mcdermott | Spouse | — | 48 | ~1892 |
Census Appearances
1920
Philadelphia, Pennsylvania
Daughter, age 1
Philadelphia, Pennsylvania · implied b. ~1919 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McDermott |
| Given Name | Mary E. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 1 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1930
Philadelphia, Pennsylvania
Daughter, age 11
Philadelphia, Pennsylvania · implied b. ~1919 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McDermott |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 11 |
| 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 |
1940
Philadelphia-County, Pennsylvania
Daughter, age 21
Philadelphia-County, Pennsylvania · implied b. ~1919 — 5 household members
| Surname | McDermott |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | Ardmore |
| 1935 Residence (County) | Montg Co |
| Occupation | File Clerk |
| Industry | Hospital |
| Class of Worker | PW |
| Hours Worked | 0 |
| Income (1939) | 240 |
| Highest Grade | Hs 1 |
| 1935 Residence | Pennsylvania |
| 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 Mcdermott across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father William Mcdermott (~0.92 confidence) and mother Elizabeth Mcdermott (~0.92 confidence) and father Martin Mcdermott (~0.92 confidence) and mother Elizabeth Mcdermott (~0.92 confidence) and father John Mcdermott (~0.92 confidence) and mother Emma Mcdermott (~0.92 confidence). The pedigree spans 1 generation with 6 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
William Mcdermott
b. ~1877
Source father
● Household
· direct · ~0.92
Mother
Elizabeth Mcdermott
b. ~1878
Source mother
● Household
· direct · ~0.92
Father
Martin Mcdermott
b. ~1890
Source father
● Household
· direct · ~0.92
Mother
Elizabeth Mcdermott
b. ~1892
Source mother
● Household
· direct · ~0.92
Father
John Mcdermott
b. ~1897
Source father
● Household
· direct · ~0.92
Mother
Emma Mcdermott
b. ~1898
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Mary Mcdermott
Daughter · 1940 · age 21 · b. ~1919 · Pennsylvania
★ You are viewing this record
Sibling
Martin Mcdermott
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Mcdermott
Sibling · 1940 · age 20
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 — Philadelphia-County, Pennsylvania
Open full size
1940 US Federal Census — Philadelphia-County, Pennsylvania
Page Contents
39 people indexed on this census page (nara:1940:m-t0627-03708-00293)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Patricia A. Liscio | 10 | Daughter | — | Pennsylvania |
| 42 | Martha Bowers | 90 | Head | — | Delaware |
| 43 | Samuel Drake | 57 | Head | Machinist Helper | Iowa |
| 44 | Esther S. Drake | 39 | Wife | — | Pennsylvania |
| 45 | Charles Drake | 25 | Son | — | Pennsylvania |
| 46 | James G. Braker | 35 | Head | Insurance Agent | Pennsylvania |
| 47 | May H. Braker | 27 | Wife | — | Pennsylvania |
| 48 | Alicia Braker | 7 | Daughter | — | Pennsylvania |
| 49 | May L. Braker | 6 | Daughter | — | Pennsylvania |
| 50 | Nancy Braker | 4 | Son | — | Pennsylvania |
| 51 | Anna Braker | 42 | Aunt | — | Pennsylvania |
| 53 | Aldo Boreani | 45 | Head | Head Operator | Pennsylvania |
| 54 | Alice Boreani | 39 | Wife | Operator | Pennsylvania |
| 55 | Louis Boreani | 16 | Son | — | Pennsylvania |
| 56 | Charles Boreani | 14 | Son | — | Pennsylvania |
| 57 | John Leonard | 32 | Head | Truck Driver | Pennsylvania |
| 58 | Josephine Leonard | 30 | Wife | — | Pennsylvania |
| 59 | Judith Leonard | 3 | Daughter | — | Pennsylvania |
| 60 | Iona Kebert | 31 | Sister in law | Stenographer | Pennsylvania |
| 61 | John Beiler | 75 | Head | Locksmith | Germany |
| 62 | Emma Beiler | 65 | Wife | — | Germany |
| 63 | Anna Harberson | 40 | Lodger | Proofreader | New Jersey |
| 64 | Ellen M. Linquist | 65 | Head | — | Pennsylvania |
| 65 | George R. Linquist | 35 | Son | Toolmaker | Maryland |
| 66 | Wynfield J. Linquist | 28 | Son | Errand Boy | Pennsylvania |
| 67 | Jane Lee | 70 | Head | — | England |
| 68 | Ada Maledon | 61 | Lodger | Nurse | Maryland |
| 69 | Alfred Meade | 25 | Head | Shoemaker | Pennsylvania |
| 70 | Mary Meade | 24 | Wife | — | Pennsylvania |
| 71 | Robert Meade | 3 | Son | — | Pennsylvania |
| 72 | James Meade | 1 | Son | — | Pennsylvania |
| 73 | Martin Mcdermott | 50 | Head | Gardner | Eire |
| 74 | Elizabeth Mcdermott | 48 | Wife | — | Eire |
| 75 | Mary Mcdermott THIS PERSON | 21 | Daughter | File Clerk | Pennsylvania |
| 76 | Edward Mcdermott | 20 | Son | Bus Boy | Pennsylvania |
| 77 | Martin Mcdermott | 17 | Son | Newspaper | Pennsylvania |
| 78 | Sarah Vanderveer | 26 | Head | — | Pennsylvania |
| 79 | Clifford Vanderveer | 8 | Son | — | Pennsylvania |
| 80 | Joan Vanderveer | 3 | Daughter | — | Pennsylvania |
Pedigree Summary
Mary + 2 siblings
Gen 1 · 6 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)