MK
Mary Koch — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Dane-County, Wisconsin
Our Model Tree links this Mary Koch across the 1930 and 1940 US Censuses in Dane-County, Wisconsin (XGBoost, ~Confirmed) — first a daughter (b.~1928), then head of a 6-person household.
Age 12
b. ~1928
Female
Daughter
Born: Wisconsin
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Dane-County, Wisconsin |
| Surname | Koch |
| Given Name | Mary Lou |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| 1935 Residence (City) | Madison City |
| 1935 Residence (County) | Dane |
| Additional Details | |
| Highest Grade | 7 |
| 1935 Residence | Same Place |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
| Township / Ward | Madison City |
| Est. Birth Year | ~1928 |
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.
6 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Oswald Koch | Head | — | 48 | ~1892 |
| William Koch | Son | — | 17 | ~1923 |
| Grace Koch | Spouse | — | 44 | ~1896 |
| Mary Koch | Daughter | — | 12 | ~1928 |
| Alan Koch | Daughter | — | 21 | ~1919 |
| Ann Koch | Daughter | — | 20 | ~1920 |
Census Appearances
1930
Dane, Wisconsin
Daughter, age 3
Dane, Wisconsin · implied b. ~1927 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Koch |
| Given Name | Mary L |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 3 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| Father's Birthplace | Wisconsin |
| Mother's Birthplace | Wisconsin |
| Occupation | none |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
1940
Dane-County, Wisconsin
Daughter, age 12
Dane-County, Wisconsin · implied b. ~1928 — 6 household members
| Surname | Koch |
| Given Name | Mary Lou |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| 1935 Residence (City) | Madison City |
| 1935 Residence (County) | Dane |
| Highest Grade | 7 |
| 1935 Residence | Same Place |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
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 Koch across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Koch
Daughter · 1940 · age 12 · b. ~1928 · Wisconsin
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Sibling
Alan Koch
Sibling · 1940 · age 21
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Ann Koch
Sibling · 1940 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
William Koch
Sibling · 1940 · age 17
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 — Dane-County, Wisconsin
Open full size
1940 US Federal Census — Dane-County, Wisconsin
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-04470-00383)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Daniel O'Connor | 83 | Father | — | Ireland |
| 42 | Francis Ellis Johnson | 55 | Head | Dean Engineering | Michigan |
| 43 | Heilende R. Johnson | 53 | Wife | — | Michigan |
| 44 | Harry J. Leader | 42 | Head | Repair Shop | Minnesota |
| 45 | Genevieve Leader | 36 | Wife | File Clerk | Wisconsin |
| 46 | Hugo Sommer | 43 | Head | Professor Dairy | Wisconsin |
| 47 | Emma Sommer | 40 | Wife | — | Wisconsin |
| 48 | Warren Sommer | 19 | Son | — | California |
| 49 | David Sommer | 18 | Son | — | Wisconsin |
| 50 | Margaret Marty | 22 | Servant | House Work | Switzerland |
| 51 | Ira B. Brown | 63 | Head | Investigator | Wisconsin |
| 52 | Laura Brown | 58 | Wife | — | Wisconsin |
| 53 | John Brown | 18 | Son | — | Wisconsin |
| 54 | Arthur Love | 44 | Head | Salesman | Wisconsin |
| 55 | Margaret Love | 36 | Wife | — | Wisconsin |
| 56 | John Love | 10 | Son | — | Wisconsin |
| 57 | Frederick Love | 8 | Son | — | Wisconsin |
| 58 | Katherine Love | 2 | Daughter | — | Wisconsin |
| 59 | Oswald J. Koch | 48 | Head | Proprietor | Wisconsin |
| 60 | Grace Koch | 44 | Wife | — | Wisconsin |
| 61 | Alan Koch | 21 | Daughter | — | Minnesota |
| 62 | Ann Koch | 20 | Daughter | — | Wisconsin |
| 63 | William Koch | 17 | Son | — | Wisconsin |
| 64 | Mary Lou Koch THIS PERSON | 12 | Daughter | — | Wisconsin |
| 65 | Marshall Glaser | 65 | Head | Law Librarian | Minnesota |
| 66 | Mabel Glaser | 65 | Wife | — | Wisconsin |
| 67 | Marshall Jr. Glaser | 27 | Son | Artist | Wisconsin |
| 68 | Morris Caldwell | 48 | Head | Director Research | Wisconsin |
| 69 | Shelia Caldwell | 30 | Wife | — | Ohio |
| 70 | Lucy Ann Caldwell | 3 | Daughter | — | Kentucky |
| 71 | Mollie Caldwell | 1 | Son | — | Kentucky |
| 72 | Verna Steffenhagen | 20 | Maid | Housework | Wisconsin |
| 73 | Frank M. Strong | 31 | Head | Prof. Chemistry | New York |
| 74 | Anne Strong | 31 | Wife | — | New York |
| 75 | Anne Strong | 11 | Daughter | — | New York |
| 76 | Frank Strong | 10 | Son | — | Wisconsin |
| 77 | Hugh Strong | 7 | Son | — | Wisconsin |
| 78 | Barbara Strong | 1 | Daughter | — | Wisconsin |
| 79 | Wilfred Batiste | 46 | Head | Branch Manager | Michigan |
| 80 | Mildred Batiste | 44 | Wife | — | Wisconsin |
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)