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Mary Mcdermott — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Clinton-County, Iowa
Our Model Tree links this Mary Mcdermott across the 1930 and 1940 US Censuses in Clinton-County, Iowa (XGBoost, ~Confirmed) — first a daughter (b.~1922), then head of a 9-person household.
Age 18
b. ~1922
Female
Daughter
Born: Iowa
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Clinton-County, Iowa |
| Surname | McDermott |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 18 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Washington Township |
| 1935 Residence (County) | Clinton |
| Additional Details | |
| Occupation | Teacher |
| Industry | Public School |
| Class of Worker | GW |
| Hours Worked | 30 |
| Income (1939) | 34 |
| Highest Grade | H 4 |
| 1935 Residence | Same place |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Occupation | Teacher |
| Township / Ward | Washington Township |
| Est. Birth Year | ~1922 |
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.
9 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Josephine Mcdermott | Daughter | — | 4 | ~1936 |
| Mary Mcdermott | Daughter | — | 18 | ~1922 |
| Anna Mcdermott | Daughter | — | 12 | ~1928 |
| Helene Mcdermott | Daughter | — | 6 | ~1934 |
| Theresa Mcdermott | Daughter | — | 12 | ~1928 |
| Lois Mcdermott | Daughter | — | 11 | ~1929 |
| Cleo Mcdermott | Head | — | 48 | ~1892 |
| Leonard Mcdermott | Son | — | 20 | ~1920 |
| Helena Mcdermott | Spouse | — | 48 | ~1892 |
Census Appearances
1930
Clinton, Iowa
Daughter, age 8
Clinton, Iowa · implied b. ~1922 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McDermott |
| Given Name | Mary C. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 8 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Clinton-County, Iowa
Daughter, age 18
Clinton-County, Iowa · implied b. ~1922 — 9 household members
| Surname | McDermott |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 18 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Washington Township |
| 1935 Residence (County) | Clinton |
| Occupation | Teacher |
| Industry | Public School |
| Class of Worker | GW |
| Hours Worked | 30 |
| Income (1939) | 34 |
| Highest Grade | H 4 |
| 1935 Residence | Same place |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
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 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Mcdermott
Daughter · 1940 · age 18 · b. ~1922 · Iowa
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Sibling
Theresa Mcdermott
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Leonard Mcdermott
Sibling · 1940 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Lois Mcdermott
Sibling · 1940 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Helene Mcdermott
Sibling · 1940 · age 6
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Josephine Mcdermott
Sibling · 1940 · age 4
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Anna Mcdermott
Sibling · 1940 · age 12
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 — Clinton-County, Iowa
Open full size
1940 US Federal Census — Clinton-County, Iowa
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01151-00365)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | John P. Hugler | 68 | Head | Operator | Iowa |
| 42 | Andrew Uplain | 27 | Head | Operator | Iowa |
| 43 | Geraldine Uplain | 23 | Wife | — | Iowa |
| 44 | Donna Uplain | 1 | Daughter | — | Iowa |
| 45 | Cleo Mcdermott | 48 | Head | Operator | Iowa |
| 46 | Helena Mcdermott | 48 | Wife | — | Iowa |
| 47 | Leonard Mcdermott | 20 | Son | Laborer | Iowa |
| 48 | Mary Mcdermott THIS PERSON | 18 | Daughter | Teacher | Iowa |
| 49 | Theresa Mcdermott | 12 | Daughter | — | Iowa |
| 50 | Anna Mcdermott | 12 | Daughter | — | Iowa |
| 51 | Lois Mcdermott | 11 | Daughter | — | Iowa |
| 52 | Helene Mcdermott | 6 | Daughter | — | Iowa |
| 53 | Josephine Mcdermott | 4 | Daughter | — | Iowa |
| 54 | Peter Figgens | 51 | Head | Operator | Belgium |
| 55 | Julia Figgens | 48 | Wife | — | Belgium |
| 56 | Benita Figgens | 19 | Daughter | — | Illinois |
| 57 | James Figgens | 18 | Son | Laborer | Illinois |
| 58 | Regis Figgens | 15 | Daughter | — | Illinois |
| 59 | Robert Figgens | 13 | Son | — | Illinois |
| 60 | Frank Figgens | 1 | Son | — | Iowa |
| 61 | Peter Figgens | 1 | Son | — | Iowa |
| 62 | Vernon Plagg | 29 | Head | Operator | Iowa |
| 63 | Esther Plagg | 22 | Wife | — | Iowa |
| 64 | Vendelle Plagg | 3 | Daughter | — | Iowa |
| 65 | Matthew Montfort | 55 | Head | Operator | Iowa |
| 66 | Minnie Montfort | 76 | Mother | — | Iowa |
| 67 | William Montfort | 50 | Brother | Laborer | Iowa |
| 68 | Agnes Montfort | 39 | Sister | — | Iowa |
| 69 | Thomas Welsh | 70 | Head | Operator | Iowa |
| 70 | William Anderson | 48 | Hired man | Laborer | Iowa |
| 71 | Ruby Anderson | 45 | Wife | Housekeeper | Iowa |
| 72 | Edward Welsh | 72 | Head | Operator | Iowa |
| 73 | Margaret Welsh | 75 | Wife | — | Iowa |
| 74 | Martha Welsh | 42 | Daughter | — | Iowa |
| 75 | Edward Welsh | 38 | Son | Laborer | Iowa |
| 76 | Frank Stevens | 52 | Head | Laborer | Kentucky |
| 77 | Rosie Stevens | 45 | Wife | — | Iowa |
| 78 | James Stevens | 21 | Son | Laborer | Iowa |
| 79 | Beula Stevens | 16 | Daughter | New Worker | Iowa |
| 80 | Ruby Stevens | 12 | Daughter | — | Iowa |
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)