TM
Thomas Mcdermott — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Baltimore-City-County, Maryland
Our Model Tree links this Thomas Mcdermott across the 1930 and 1940 US Censuses in Baltimore-City-County, Maryland (XGBoost, ~Confirmed) — first a son (b.~1925), then head of a 8-person household.
Age 15
b. ~1925
Male
Son
Born: Maryland
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Baltimore-City-County, Maryland |
| Surname | McDermott |
| Given Name | Thomas P. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 15 |
| Marital Status | Single |
| Birthplace | Maryland |
| 1935 Residence (City) | Baltimore City |
| 1935 Residence (County) | Baltimore City |
| Additional Details | |
| Class of Worker | 0 |
| Highest Grade | Yes 8 |
| 1935 Residence | Same House |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
| Township / Ward | Baltimore City |
| Est. Birth Year | ~1925 |
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.
8 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Thomas | Age | Birth yr |
|---|---|---|---|---|
| Joan Mcdermott | Daughter | — | 10 | ~1930 |
| Thomas Mcdermott | Son | — | 15 | ~1925 |
| Joseph Mcdermott | Head | — | 51 | ~1889 |
| Alexandrine Mcdermott | Daughter | — | 25 | ~1915 |
| Elizabeth Mcdermott | Daughter | — | 19 | ~1921 |
| Mary Mcdermott | Daughter | — | 21 | ~1919 |
| Nancy Mcdermott | Daughter | — | 19 | ~1921 |
| Marguerite Mcdermott | Spouse | — | 51 | ~1889 |
Census Appearances
1930
Baltimore, Maryland
Son, age 5
Baltimore, Maryland · implied b. ~1925 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McDermott |
| Given Name | Thomas |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 5 |
| Marital Status | Single |
| Birthplace | Maryland |
| Father's Birthplace | Maryland |
| Mother's Birthplace | Maryland |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
1940
Baltimore-City-County, Maryland
Son, age 15
Baltimore-City-County, Maryland · implied b. ~1925 — 8 household members
| Surname | McDermott |
| Given Name | Thomas P. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 15 |
| Marital Status | Single |
| Birthplace | Maryland |
| 1935 Residence (City) | Baltimore City |
| 1935 Residence (County) | Baltimore City |
| Class of Worker | 0 |
| Highest Grade | Yes 8 |
| 1935 Residence | Same House |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
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 Thomas Mcdermott across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Thomas Mcdermott
Son · 1940 · age 15 · b. ~1925 · Maryland
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Sibling
Mary Mcdermott
Sibling · 1940 · age 21
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Elizabeth Mcdermott
Sibling · 1940 · age 19
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joan Mcdermott
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Alexandrine Mcdermott
Sibling · 1940 · age 25
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Nancy Mcdermott
Sibling · 1940 · age 19
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 — Baltimore-City-County, Maryland
Open full size
1940 US Federal Census — Baltimore-City-County, Maryland
Page Contents
21 people indexed on this census page (nara:1940:m-t0627-01533-00122)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Cordelia Kelley | 40 | Daughter | — | Maryland |
| 2 | William W. Zeller | 41 | Head | Proprietor | Maryland |
| 3 | Irene G. Zeller | 41 | Wife | — | Maryland |
| 4 | William W. Jr. Zeller | 18 | Son | — | Maryland |
| 5 | Thomas F. Zeller | 13 | Son | — | Maryland |
| 6 | Hoyt N. Waters | 53 | Head | Billing Clerk | North Carolina |
| 7 | Ruth E. Waters | 45 | Wife | — | Maryland |
| 8 | John N. Waters | 26 | Son | Photographer | Maryland |
| 9 | Thomas B. Waters | 23 | Son | Photographer | Maryland |
| 10 | Joseph A. Mcdermott | 51 | Head | Purchasing Agent | Maryland |
| 11 | Marguerite L. Mcdermott | 51 | Wife | — | Virginia |
| 12 | Alexandrine Mcdermott | 25 | Daughter | Stenographer | Maryland |
| 13 | Mary Clara Mcdermott | 21 | Daughter | Record Clerk | Maryland |
| 14 | Nancy Mcdermott | 19 | Daughter | — | Maryland |
| 15 | Thomas P. Mcdermott THIS PERSON | 15 | Son | — | Maryland |
| 16 | Joan Marie Mcdermott | 10 | Daughter | — | Maryland |
| 17 | Elizabeth Mcdermott | 19 | Daughter | — | Maryland |
| 18 | Josie M. Klein | 55 | Head | — | Maryland |
| 19 | William F. Seibold | 35 | Son | Salesman | Maryland |
| 20 | Mary A.W. Kniss | 66 | Head | — | Maryland |
| 21 | E. Maude Crawford | 59 | Lodger | — | Maryland |
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)