MK
Mary Koch — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Livingston-County, Michigan
Our Model Tree links this Mary Koch across the 1930 and 1940 US Censuses in Livingston-County, Michigan (XGBoost, ~Confirmed) — first a daughter (b.~1926), then head of a 8-person household.
Age 14
b. ~1926
Female
Daughter
Born: Michigan
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Livingston-County, Michigan |
| Surname | Koch |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Michigan |
| 1935 Residence (City) | R |
| 1935 Residence (County) | Washtenaw |
| Additional Details | |
| Highest Grade | G-6 |
| 1935 Residence | Michigan |
| Birth State | Michigan |
| Birth Country | United States |
| Birthplace (normalized) | michigan |
| Township / Ward | Genoa Twp |
| Est. Birth Year | ~1926 |
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 Mary | Age | Birth yr |
|---|---|---|---|---|
| Gertrude Koch | Daughter | — | 17 | ~1923 |
| Edward Koch | Head | — | 48 | ~1892 |
| John Koch | Son | — | 3 | ~1937 |
| Edward Koch | Son | — | 11 | ~1929 |
| Mary Koch | Daughter | — | 14 | ~1926 |
| Ruth Koch | Daughter | — | 22 | ~1918 |
| Mary Koch | Spouse | — | 47 | ~1893 |
| Margaret Koch | Daughter | — | 19 | ~1921 |
Census Appearances
1930
Washtenaw, Michigan
Daughter, age 4
Washtenaw, Michigan · implied b. ~1926 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Koch |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 4 |
| Marital Status | Single |
| Birthplace | Michigan |
| Father's Birthplace | Michigan |
| Mother's Birthplace | Michigan |
| Can Read/Write | No |
| Birth State | Michigan |
| Birth Country | United States |
| Birthplace (normalized) | michigan |
1940
Livingston-County, Michigan
Daughter, age 14
Livingston-County, Michigan · implied b. ~1926 — 8 household members
| Surname | Koch |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Michigan |
| 1935 Residence (City) | R |
| 1935 Residence (County) | Washtenaw |
| Highest Grade | G-6 |
| 1935 Residence | Michigan |
| Birth State | Michigan |
| Birth Country | United States |
| Birthplace (normalized) | michigan |
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 14 · b. ~1926 · Michigan
★ You are viewing this record
Sibling
Gertrude Koch
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Margaret Koch
Sibling · 1940 · age 19
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Koch
Sibling · 1940 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Koch
Sibling · 1940 · age 3
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Ruth Koch
Sibling · 1940 · age 22
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 — Livingston-County, Michigan
Open full size
1940 US Federal Census — Livingston-County, Michigan
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01780-00154)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Robert Howell | 34 | Son | Laborer | Ohio |
| 2 | John H. Wermeister | 57 | Head | Farm Operator | Michigan |
| 3 | Gladys Wermeister | 30 | Wife | — | Michigan |
| 4 | John C. Wermeister | 22 | Son | Farm Hand | Michigan |
| 5 | John C. Wermeister | 78 | Head | — | Michigan |
| 6 | Marie Wermeister | 69 | Wife | — | Michigan |
| 7 | Robert E. Barton | 51 | Head | Camp Supervisor | Canada English |
| 8 | Marguerite Barton | 37 | Wife | — | Michigan |
| 9 | Robert E. Jr. Barton | 12 | Son | — | Michigan |
| 10 | Thomas Barton | 10 | Son | — | Michigan |
| 11 | Hannah Blanchard | 51 | Head | — | Wisconsin |
| 12 | Myrtha Blanchard | 19 | Daughter | Clerk | Minnesota |
| 13 | George Graham | 51 | Lodger | Laborer | Michigan |
| 14 | Carl Birkenstock | 50 | Head | Farm Operator | Michigan |
| 15 | Ethel F. Birkenstock | 47 | Wife | — | Michigan |
| 16 | Horace Birkenstock | 23 | Son | Carpenter | Michigan |
| 17 | Fred Wollenhaupt | 71 | Head | Farm Operator | Germany |
| 18 | Mattie E. Wollenhaupt | 67 | Wife | — | Michigan |
| 19 | Dewey Wollenhaupt | 41 | Son | Mechanic | Michigan |
| 20 | Emma Bieber | 67 | Head | — | Michigan |
| 21 | William Dorr | 73 | Boarder | — | Michigan |
| 22 | Elizabeth Pless | 71 | Head | — | Michigan |
| 23 | George Dodge | 24 | Lodger | Farm Hand | Michigan |
| 24 | John D. Murninghan | 18 | Lodger | Farm Hand | Michigan |
| 25 | Charles H. Pless | 76 | Head | — | Michigan |
| 26 | Mary F. Pless | 77 | Wife | — | Michigan |
| 27 | Albert Zimmerman | 42 | Head | Plater | Michigan |
| 28 | Elvira Zimmerman | 37 | Wife | — | So. Dakota |
| 29 | Edward Koch | 48 | Head | Tavern Operator | Michigan |
| 30 | Mary Koch | 47 | Wife | — | Michigan |
| 31 | Ruth Koch | 22 | Daughter | — | Michigan |
| 32 | Margaret Koch | 19 | Daughter | Machine Operator | Michigan |
| 33 | Gertrude Koch | 17 | Daughter | — | Michigan |
| 34 | Mary Koch THIS PERSON | 14 | Daughter | — | Michigan |
| 35 | Edward Koch | 11 | Son | — | Michigan |
| 36 | John Koch | 3 | Son | — | Michigan |
| 37 | Homer J. Bangher | 48 | Head | Pattern Maker | Indiana |
| 38 | Elois M. Bangher | 37 | Wife | — | Canada English |
| 39 | Louie Bangher | 10 | Daughter | — | Michigan |
| 40 | Mable Bangher | 6 | Daughter | — | Michigan |
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)