MK
Mary Koch — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Jefferson-County, Kentucky
Our Model Tree links this Mary Koch across the 1930 and 1940 US Censuses in Jefferson-County, Kentucky (XGBoost, ~Confirmed) — first a spouse (b.~1902), then head of a 7-person household.
Age 38
b. ~1902
Female
Spouse
Born: Kentucky
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Jefferson-County, Kentucky |
| Surname | Koch |
| Given Name | Mary L. |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 38 |
| Marital Status | Married |
| Birthplace | Kentucky |
| 1935 Residence (City) | Louisville, City |
| 1935 Residence (County) | Jefferson |
| Additional Details | |
| Income (1939) | 0 |
| Highest Grade | No 5 |
| 1935 Residence | Same place |
| Birth State | Kentucky |
| Birth Country | United States |
| Birthplace (normalized) | kentucky |
| Township / Ward | Louisville City |
| Est. Birth Year | ~1902 |
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 |
|---|---|---|---|---|
| Lawrence Koch | Head | — | 41 | ~1899 |
| Irene Koch | Son | — | 18 | ~1922 |
| Mary Koch | Spouse | — | 38 | ~1902 |
| Delores Koch | Daughter | — | 16 | ~1924 |
| Evelyn Koch | Daughter | — | 14 | ~1926 |
| Delbert Koch | Son | — | 9 | ~1931 |
| Mary Koch | Daughter | — | 12 | ~1928 |
Census Appearances
1930
Jefferson, Kentucky
Other, age 29
Jefferson, Kentucky · implied b. ~1901 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Koch |
| Given Name | Mary L. |
| Relationship to Head | Wife-H |
| Sex | F |
| Color / Race | White |
| Age | 29 |
| Marital Status | Married |
| Birthplace | Kentucky |
| Age at First Marriage | 18 |
| Father's Birthplace | Kentucky |
| Mother's Birthplace | Kentucky |
| Can Read/Write | Yes |
| Birth State | Kentucky |
| Birth Country | United States |
| Birthplace (normalized) | kentucky |
1940
Jefferson-County, Kentucky
Spouse, age 38
Jefferson-County, Kentucky · implied b. ~1902 — 7 household members
| Surname | Koch |
| Given Name | Mary L. |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 38 |
| Marital Status | Married |
| Birthplace | Kentucky |
| 1935 Residence (City) | Louisville, City |
| 1935 Residence (County) | Jefferson |
| Income (1939) | 0 |
| Highest Grade | No 5 |
| 1935 Residence | Same place |
| Birth State | Kentucky |
| Birth Country | United States |
| Birthplace (normalized) | kentucky |
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
Spouse · 1940 · age 38 · b. ~1902 · Kentucky
★ You are viewing this record
Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Jefferson-County, Kentucky
Open full size
1940 US Federal Census — Jefferson-County, Kentucky
Page Contents
39 people indexed on this census page (nara:1940:m-t0627-01374-00538)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Mattie Stewart | 69 | Head | — | Indiana |
| 2 | George M. Stewart | 47 | Son | Wall Paper Cleaner | Indiana |
| 3 | Punt Williams | 67 | Boarder | Night Watchman | Kentucky |
| 4 | Charles Orr | 69 | Boarder | Leaf Roller | Kentucky |
| 5 | Lawrence J. Koch | 41 | Head | Miller | Kentucky |
| 6 | Mary L. Koch THIS PERSON | 38 | Wife | — | Kentucky |
| 7 | Irene E. Koch | 18 | Son | New Worker | Kentucky |
| 8 | Delores M. Koch | 16 | Daughter | — | Kentucky |
| 9 | Evelyn M. Koch | 14 | Daughter | — | Kentucky |
| 10 | Mary C. Koch | 12 | Daughter | — | Kentucky |
| 11 | Delbert E. Koch | 9 | Son | — | Kentucky |
| 12 | Harold C. Short | 35 | Head | Milk Salesman | Kentucky |
| 13 | Mildred Short | 26 | Wife | — | Kentucky |
| 14 | Betty J. Short | 12 | Daughter | — | Kentucky |
| 15 | Harold K. Short | 9 | Son | — | Kentucky |
| 16 | Patricia A. Short | 3 | Daughter | — | Kentucky |
| 17 | Robert J. Stafford | 49 | Head | Service Man | Kentucky |
| 18 | Carrie Stafford | 49 | Wife | — | Kentucky |
| 19 | Christian Busch | 81 | Father-in-law | — | Germany |
| 20 | Marie A. Busch | 75 | Mother-in-law | — | Germany |
| 21 | Elmer J. Roebottom | 37 | Head | Printer | Indiana |
| 22 | Mildred E. Roebottom | 31 | Wife | — | Indiana |
| 23 | Elmer J. Jr. Roebottom | 9 | Son | — | Indiana |
| 24 | Everett L. Rager | 20 | Brother-in-law | Shipping Clerk | Indiana |
| 25 | Catherine E. Jefferson | 27 | Sister-in-law | — | Indiana |
| 26 | Robert J. Jefferson | 1 | Nephew | — | Kentucky |
| 27 | John F. Kanzler | 47 | Head | Manager-Owner | Kentucky |
| 28 | Elsie E. Kanzler | 45 | Wife | — | Kentucky |
| 29 | Robert L. Kanzler | 18 | Son | Station Attendant | Kentucky |
| 30 | Joseph D. Coy | 41 | Head | Barrel Filler | Kentucky |
| 31 | Elizabeth F. Coy | 36 | Wife | — | Kentucky |
| 32 | Geraldine F. Coy | 15 | Daughter | — | Kentucky |
| 33 | Joseph M. Coy | 13 | Son | — | Kentucky |
| 34 | Martha M. Coy | 13 | Daughter | — | Kentucky |
| 35 | Lola J. Coy | 12 | Daughter | — | Kentucky |
| 36 | Edward J. Coy | 7 | Son | — | Kentucky |
| 37 | Jerry J. Coy | 2 | Son | — | Kentucky |
| 38 | Millard C. Rhodes | 45 | Head | Helper Blacksmith | Kentucky |
| 39 | Lorena M. Rhodes | 48 | Wife | — | Kentucky |
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)