WK
William Koch — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Vanderburgh-County, Indiana
Our Model Tree links this William Koch across the 1930 and 1940 US Censuses in Vanderburgh-County, Indiana (XGBoost, ~Confirmed) — first a son (b.~1927), then head of a 6-person household.
Age 13
b. ~1927
Male
Son
Born: Indiana
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Vanderburgh-County, Indiana |
| Surname | Koch |
| Given Name | William B |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Indiana |
| 1935 Residence (City) | Evansville City |
| 1935 Residence (County) | Vanderburgh |
| Additional Details | |
| Income (1939) | 0 |
| Highest Grade | H 7 |
| 1935 Residence | Same place |
| Birth State | Indiana |
| Birth Country | United States |
| Birthplace (normalized) | indiana |
| Township / Ward | Evansville City |
| Est. Birth Year | ~1927 |
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 William | Age | Birth yr |
|---|---|---|---|---|
| William Koch | Son | — | 13 | ~1927 |
| John Koch | Son | — | 14 | ~1926 |
| John Koch | Head | — | 45 | ~1895 |
| Barbara Koch | Daughter | — | 9 | ~1931 |
| Helen Koch | Spouse | — | 42 | ~1898 |
| Helen Koch | Daughter | — | 16 | ~1924 |
Census Appearances
1930
Vanderburgh, Indiana
Son, age 3
Vanderburgh, Indiana · implied b. ~1927 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Koch |
| Given Name | William B. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 3 |
| Marital Status | Single |
| Birthplace | Indiana |
| Father's Birthplace | Indiana |
| Mother's Birthplace | Indiana |
| Birth State | Indiana |
| Birth Country | United States |
| Birthplace (normalized) | indiana |
1940
Vanderburgh-County, Indiana
Son, age 13
Vanderburgh-County, Indiana · implied b. ~1927 — 6 household members
| Surname | Koch |
| Given Name | William B |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Indiana |
| 1935 Residence (City) | Evansville City |
| 1935 Residence (County) | Vanderburgh |
| Income (1939) | 0 |
| Highest Grade | H 7 |
| 1935 Residence | Same place |
| Birth State | Indiana |
| Birth Country | United States |
| Birthplace (normalized) | indiana |
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 William Koch across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
William Koch
Son · 1940 · age 13 · b. ~1927 · Indiana
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Sibling
John Koch
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Barbara Koch
Sibling · 1940 · age 9
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Helen Koch
Sibling · 1940 · age 16
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 — Vanderburgh-County, Indiana
Open full size
1940 US Federal Census — Vanderburgh-County, Indiana
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01113-01003)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Elijah Hall | 61 | Head | Road Worker | Kentucky |
| 2 | Ida Hall | 55 | Wife | — | Illinois |
| 3 | John A Koch | 45 | Head | Cost Accountant | Indiana |
| 4 | Helen E D Koch | 42 | Wife | — | Indiana |
| 5 | Helen Elizabeth Koch | 16 | Daughter | — | Indiana |
| 6 | John H Koch | 14 | Son | — | Indiana |
| 7 | William B Koch THIS PERSON | 13 | Son | — | Indiana |
| 8 | Barbara J Koch | 9 | Daughter | — | Indiana |
| 9 | Joe I Reising | 54 | Head | Coffee Roaster | Indiana |
| 10 | Anna Reising | 49 | Wife | — | Indiana |
| 11 | Ben Craig | 27 | Step Son | — | Indiana |
| 12 | Raymond Craig | 25 | Step Son | Inspector | Indiana |
| 13 | Manford Craig | 20 | Step Son | Helper | Indiana |
| 14 | Robert Craig | 18 | Step Son | Lineman | Indiana |
| 15 | Elvis Kinder | 51 | Head | Deliveryman | Indiana |
| 16 | Inez Kinder | 48 | Wife | — | Indiana |
| 17 | Wilber Kinder | 30 | Son | Deliveryman | Indiana |
| 18 | Alfred Kinder | 17 | Son | — | Indiana |
| 19 | John Wm Board | 21 | Head | Laborer | Kentucky |
| 20 | Helen L Board | 19 | Wife | — | Kentucky |
| 21 | John Wm Jr Board | 1 | Son | — | Indiana |
| 22 | Chas H Ruff | 56 | Head | Furniture Worker | Indiana |
| 23 | Anna Ruff | 51 | Wife | — | Germany |
| 24 | Anna R Ruff | 30 | Daughter | Clerical | Indiana |
| 25 | Chas E Ruff | 27 | Son | Shipping Clerk | Indiana |
| 26 | Jacob Hahn | 40 | Head | Foreman | Indiana |
| 27 | Ella Hahn | 43 | Wife | — | Kentucky |
| 28 | Samuel Main | 30 | Head | Fireman | Kentucky |
| 29 | Helen Main | 30 | Wife | — | Indiana |
| 30 | Jerome Main | 8 | Son | — | Indiana |
| 31 | Marilyn Main | 6 | Daughter | — | Indiana |
| 32 | Edgar Baumgartner | 29 | Head | Stockman | Indiana |
| 33 | Virginia Baumgartner | 24 | Wife | Clerical | Indiana |
| 34 | Norman Baumgartner | 22 | Brother | Laborer | Indiana |
| 35 | Frank James | 18 | Head | Laborer | Indiana |
| 36 | Velma Ruth James | 16 | Wife | — | Indiana |
| 37 | August P Gebhardt | 58 | Head | Furniture Worker | Indiana |
| 38 | Emma Gebhardt | 58 | Wife | — | Colorado |
| 39 | Ben Wall | 74 | Head | — | Indiana |
| 40 | Joe Wall | 40 | Son | Laborer | Indiana |
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)