MK
Mary Kerr — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Black-Hawk-County, Iowa
Our Model Tree links this Mary Kerr across the 1930 and 1940 US Censuses in Black-Hawk-County, Iowa (XGBoost, ~Confirmed) — first a daughter (b.~1921), then head of a 7-person household.
Age 19
b. ~1921
Female
Daughter
Born: Iowa
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Black-Hawk-County, Iowa |
| Surname | Kerr |
| Given Name | Mary |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 19 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Eagle Twp. |
| 1935 Residence (County) | Blackhawk |
| Additional Details | |
| Occupation | housework |
| Class of Worker | PW |
| Hours Worked | 60 |
| Income (1939) | 0 |
| Highest Grade | No 12 |
| 1935 Residence | Same place |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Occupation | Housework |
| Township / Ward | Eagle Twp |
| Est. Birth Year | ~1921 |
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.
7 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Beatrice Kerr | Daughter | — | 21 | ~1919 |
| Marjorie Kerr | Daughter | — | 23 | ~1917 |
| Mary Kerr | Daughter | — | 19 | ~1921 |
| Gertrude Kerr | Daughter | — | 15 | ~1925 |
| John Kerr | Head | — | 55 | ~1885 |
| Harriet Kerr | Daughter | — | 22 | ~1918 |
| Beatrice Kerr | Spouse | — | 55 | ~1885 |
Census Appearances
1930
Black Hawk, …
Daughter, age 9
Black Hawk, Iowa · implied b. ~1921 — 16 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kerr |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 9 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Occupation | none |
| Can Read/Write | Yes |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Black-Hawk-County, Iowa
Daughter, age 19
Black-Hawk-County, Iowa · implied b. ~1921 — 7 household members
| Surname | Kerr |
| Given Name | Mary |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 19 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Eagle Twp. |
| 1935 Residence (County) | Blackhawk |
| Occupation | housework |
| Class of Worker | PW |
| Hours Worked | 60 |
| Income (1939) | 0 |
| Highest Grade | No 12 |
| 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 Kerr across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Kerr
Daughter · 1940 · age 19 · b. ~1921 · Iowa
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Sibling
Gertrude Kerr
Sibling · 1940 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Beatrice Kerr
Sibling · 1940 · age 21
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Harriet Kerr
Sibling · 1940 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Marjorie Kerr
Sibling · 1940 · age 23
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 — Black-Hawk-County, Iowa
Open full size
1940 US Federal Census — Black-Hawk-County, Iowa
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01139-00455)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Margaret Buhrman | 35 | wife | — | Germany |
| 2 | Oliver Kulkrabek | 26 | head | Farm Operator | Iowa |
| 3 | Pearl Kulkrabek | 20 | wife | — | Iowa |
| 4 | Nancy Kulkrabek | 4 | daughter | — | Iowa |
| 5 | Vincent Kulkrabek | 3 | son | — | Iowa |
| 6 | Verl Raum | 29 | hired hand | Farm Laborer | Iowa |
| 7 | Gloria Mcneil | 14 | sister in law | — | Iowa |
| 8 | Joseph Zellig | 73 | head | Farm Laborer | Wisconsin |
| 9 | Susan Zellig | 67 | wife | — | Illinois |
| 10 | Lawrence Zellig | 42 | son | Farmer | Iowa |
| 11 | Edward Zellig | 33 | son | Farm | Iowa |
| 12 | Frances Zellig | 28 | daughter | Housewife | Iowa |
| 13 | Leo Pieter | 42 | head | Farm Operator | Iowa |
| 14 | Angela Pieter | 42 | wife | — | Illinois |
| 15 | Harold Pieter | 18 | son | Farm Laborer | Iowa |
| 16 | Luella Pieter | 16 | daughter | — | Iowa |
| 17 | Dorothy Pieter | 13 | daughter | — | Iowa |
| 18 | Olivia Pieter | 10 | daughter | — | Iowa |
| 19 | Donald Pieter | 2 | son | — | Iowa |
| 20 | John D. Kerr | 55 | head | Farm Operator | Iowa |
| 21 | Beatrice Kerr | 55 | wife | — | Iowa |
| 22 | Marjorie A. Kerr | 23 | daughter | — | Iowa |
| 23 | Harriet L. Kerr | 22 | daughter | — | Iowa |
| 24 | Beatrice Kerr | 21 | daughter | — | Iowa |
| 25 | Mary Kerr THIS PERSON | 19 | daughter | Housework | Iowa |
| 26 | Gertrude Kerr | 15 | daughter | — | Iowa |
| 27 | Amer Conry | 58 | head | Farm Operator | Iowa |
| 28 | Catherine Conry | 85 | mother | — | Iowa |
| 29 | Doris Conry | 23 | sister | House Keeper | Iowa |
| 30 | Lucile Wetry | 36 | sister | — | Iowa |
| 31 | Robert Wetry | 2 | nephew | — | Iowa |
| 32 | William Wetry | 2 | nephew | — | Iowa |
| 33 | Arlo Schlemmer | 43 | hired hand | Farm Laborer | Iowa |
| 34 | Sylvester Mcgarvey | 27 | head | Farm Operator | Iowa |
| 35 | Blanche Mcgarvey | 25 | wife | — | Iowa |
| 36 | James Jason Mcgarvey | 4 | son | — | Iowa |
| 37 | Marguerite Mcgarvey | 2 | daughter | — | Iowa |
| 38 | Mary Alice Mcgarvey | 1 | daughter | — | Iowa |
| 39 | James Sr. Mcgarvey | 67 | father | Farmer | Eire |
| 40 | Frank V. Conry | 50 | head | Farm Operator | Iowa |
Related Census Records
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)