JK
John Kovach — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Mahoning-County, Ohio
Our Model Tree links this John Kovach across the 1930 and 1940 US Censuses in Mahoning-County, Ohio (XGBoost, ~Confirmed) — first a son (b.~1919), then head of a 11-person household.
Age 21
b. ~1919
Male
Son
Born: Ohio
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Mahoning-County, Ohio |
| Surname | Kovach |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Ohio |
| 1935 Residence (City) | Campbell City |
| 1935 Residence (County) | Mahoning |
| Additional Details | |
| Occupation | Laborer |
| Industry | Steel Mill |
| Class of Worker | PW |
| Hours Worked | 4 |
| Income (1939) | 120 |
| Highest Grade | C 2 |
| 1935 Residence | Same place |
| Birth State | Ohio |
| Birth Country | United States |
| Birthplace (normalized) | ohio |
| Occupation | Laborer |
| Township / Ward | Campbell City |
| Est. Birth Year | ~1919 |
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.
11 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Anna Kovach | Daughter | — | 9 | ~1931 |
| Jean Kovach | Daughter | — | 5 | ~1935 |
| Paul Kovach | Son | — | 17 | ~1923 |
| Mary Kovach | Spouse | — | 44 | ~1896 |
| Margaret Kovach | Daughter | — | 14 | ~1926 |
| George Kovach | Son | — | 16 | ~1924 |
| Michal Kovach | Son | — | 19 | ~1921 |
| Edward Kovach | Son | — | 11 | ~1929 |
| Mike Kovach | Head | — | 48 | ~1892 |
| John Kovach | Son | — | 21 | ~1919 |
| Joseph Kovach | Son | — | 13 | ~1927 |
Census Appearances
1930
Mahoning, Ohio
Son, age 11
Mahoning, Ohio · implied b. ~1919 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Kovach |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Ohio |
| Father's Birthplace | Jugoslavia |
| Mother's Birthplace | Jugoslavia |
| Can Read/Write | Yes |
| Birth State | Ohio |
| Birth Country | United States |
| Birthplace (normalized) | ohio |
1940
Mahoning-County, Ohio
Son, age 21
Mahoning-County, Ohio · implied b. ~1919 — 11 household members
| Surname | Kovach |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Ohio |
| 1935 Residence (City) | Campbell City |
| 1935 Residence (County) | Mahoning |
| Occupation | Laborer |
| Industry | Steel Mill |
| Class of Worker | PW |
| Hours Worked | 4 |
| Income (1939) | 120 |
| Highest Grade | C 2 |
| 1935 Residence | Same place |
| Birth State | Ohio |
| Birth Country | United States |
| Birthplace (normalized) | ohio |
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 John Kovach across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Kovach
Son · 1940 · age 21 · b. ~1919 · Ohio
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Sibling
Margaret Kovach
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Michal Kovach
Sibling · 1940 · age 19
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Paul Kovach
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Jean Kovach
Sibling · 1940 · age 5
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Kovach
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Anna Kovach
Sibling · 1940 · age 9
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Kovach
Sibling · 1940 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
George Kovach
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 — Mahoning-County, Ohio
Open full size
1940 US Federal Census — Mahoning-County, Ohio
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03109-00094)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Anna Matacic | 24 | Daughter | Waitress | Ohio |
| 2 | Joseph Matacic | 20 | Son | Clerk | Ohio |
| 3 | John Hudak | 47 | Head | Rigger | Slovakia |
| 4 | Mary Hudak | 43 | Wife | — | Slovakia |
| 5 | John Hudak | 23 | Son | Labour | Ohio |
| 6 | Mary Hudak | 20 | Daughter | New Worker | Ohio |
| 7 | Mike Hudak | 15 | Son | Student | Ohio |
| 8 | Mike Kovach | 48 | Head | Pipe Cutter | Slovakia |
| 9 | Mary Kovach | 44 | Wife | — | Slovakia |
| 10 | John Kovach THIS PERSON | 21 | Son | Laborer | Ohio |
| 11 | Michal Kovach | 19 | Son | Messenger Boy | Ohio |
| 12 | Paul Kovach | 17 | Son | Student | Ohio |
| 13 | George Kovach | 16 | Son | Student | Ohio |
| 14 | Margaret Kovach | 14 | Daughter | Student | Ohio |
| 15 | Joseph Kovach | 13 | Son | — | Ohio |
| 16 | Edward Kovach | 11 | Son | — | Ohio |
| 17 | Anna Kovach | 9 | Daughter | — | Ohio |
| 18 | Jean Kovach | 5 | Daughter | — | Ohio |
| 19 | Ignatz Rochar | 58 | Head | Truck Driver | Yugo-Slav |
| 20 | Mildred Rochar | 44 | Wife | — | Yugo-Slav |
| 21 | Mary Rochar | 7 | Daughter | — | Ohio |
| 22 | Ned Popovich | 50 | Lodger | Truck Driver | Yugo-Slav |
| 23 | John Trill | 53 | Head | Rigger | Slovakia |
| 24 | Mary Trill | 49 | Wife | — | Slovakia |
| 25 | Mike Trill | 28 | Son | Shipper | Ohio |
| 26 | Mary Trill | 27 | Daughter | Maid | Ohio |
| 27 | Helen Trill | 24 | Daughter | Maid | Ohio |
| 28 | John Trill | 23 | Son | Labour | Ohio |
| 29 | George Trill | 21 | Son | New Worker | Ohio |
| 30 | Joseph Trill | 18 | Son | New Worker | Ohio |
| 31 | Albert Trill | 11 | Son | — | Ohio |
| 32 | Frances Grzywacz | 25 | Head | Typist | Ohio |
| 33 | Joseph Grzywacz | 22 | Brother | Steel Worker | Ohio |
| 34 | Julius Grzywacz | 20 | Brother | Truck Driver | Ohio |
| 35 | Stanley Grzywacz | 18 | Brother | Sign Painter | Ohio |
| 36 | Andrew Grzywacz | 16 | Brother | Student | Ohio |
| 37 | Helen Grzywacz | 13 | Sister | — | Ohio |
| 38 | Peter Horchnak | 44 | Head | Car Loader | Slovakia |
| 39 | Helen Horchnak | 44 | Wife | — | Slovakia |
| 40 | Daniel Horchnak | 24 | Son | Stencil | Ohio |
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)