JL
John Leach — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Milwaukee-County, Wisconsin
Our Model Tree links this John Leach across the 1930 and 1940 US Censuses in Milwaukee-County, Wisconsin (XGBoost, ~Confirmed) — first a son (b.~1915), then head of a 6-person household.
Age 25
b. ~1915
Male
Son
Born: Wisconsin
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Milwaukee-County, Wisconsin |
| Surname | Leach |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| 1935 Residence (City) | Milwaukee |
| 1935 Residence (County) | Milwaukee |
| Additional Details | |
| Occupation | Machinist |
| Industry | Machinery |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 1413 |
| Highest Grade | H 4 |
| 1935 Residence | Same place |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
| Occupation | Machinist |
| Township / Ward | Milwaukee |
| Est. Birth Year | ~1915 |
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 John | Age | Birth yr |
|---|---|---|---|---|
| Mildred Leach | Daughter | — | 30 | ~1910 |
| Harold Leach | Son | — | 27 | ~1913 |
| Marcella Leach | Daughter | — | 33 | ~1907 |
| John Leach | Son | — | 25 | ~1915 |
| Abbie Leach | Spouse | — | 66 | ~1874 |
| John Leach | Head | — | 69 | ~1871 |
Census Appearances
1930
Milwaukee, Wisconsin
Son, age 14
Milwaukee, Wisconsin · implied b. ~1916 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Lach |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| Father's Birthplace | Wisconsin |
| Mother's Birthplace | Wisconsin |
| Can Read/Write | Yes |
| Birth State | Wisconsin |
| Birth Country | United States |
| Birthplace (normalized) | wisconsin |
1940
Milwaukee-County, Wisconsin
Son, age 25
Milwaukee-County, Wisconsin · implied b. ~1915 — 6 household members
| Surname | Leach |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Wisconsin |
| 1935 Residence (City) | Milwaukee |
| 1935 Residence (County) | Milwaukee |
| Occupation | Machinist |
| Industry | Machinery |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 1413 |
| Highest Grade | H 4 |
| 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 John Leach across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Leach
Son · 1940 · age 25 · b. ~1915 · Wisconsin
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Sibling
Harold Leach
Sibling · 1940 · age 27
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Mildred Leach
Sibling · 1940 · age 30
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Marcella Leach
Sibling · 1940 · age 33
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 — Milwaukee-County, Wisconsin
Open full size
1940 US Federal Census — Milwaukee-County, Wisconsin
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-04563-00260)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Ruth Schneider | 10 | Daughter | — | Wisconsin |
| 42 | Kenneth Schneider | 5 | Son | — | Wisconsin |
| 43 | Gustave Hoist | 43 | Head | Baker | Bohemia |
| 44 | Margaret Hoist | 36 | Wife | — | Wisconsin |
| 45 | Gretchen Hoist | 1 | Son | — | Wisconsin |
| 46 | Charles Defek | 35 | Head | Machinist | Wisconsin |
| 47 | Leona Defek | 31 | Wife | — | Wisconsin |
| 48 | Charles Defek | 12 | Son | — | Wisconsin |
| 49 | Patricia Defek | 11 | Daughter | — | Wisconsin |
| 50 | Jerome Defek | 9 | Son | — | Wisconsin |
| 51 | Robert Defek | 8 | Son | — | Wisconsin |
| 52 | Gregory Defek | 6 | Son | — | Wisconsin |
| 53 | Marvin Defek | 3 | Son | — | Wisconsin |
| 54 | John A. Leach | 69 | Head | — | Wisconsin |
| 55 | Abbie Leach | 66 | Wife | — | Wisconsin |
| 56 | Marcella Leach | 33 | Daughter | Cashier | Wisconsin |
| 57 | Mildred Leach | 30 | Daughter | Clerical Work | Wisconsin |
| 58 | Harold Leach | 27 | Son | Store Helper | Wisconsin |
| 59 | John Leach THIS PERSON | 25 | Son | Machinist | Wisconsin |
| 60 | Charles J. Hulgard | 65 | Head | — | Wisconsin |
| 61 | Margaret Hulgard | 56 | Wife | — | Wisconsin |
| 62 | Hans Wagner | 34 | Head | Painter & Decor. | Germany |
| 63 | Anne Wagner | 28 | Wife | — | Belgium |
| 64 | Clara Wagner | 1 | Daughter | — | Wisconsin |
| 65 | Fritz Broecke | 52 | Lodger | Labour - Janitor | Germany |
| 66 | Alfred Amundsen | 52 | Head | Machinist | Norway |
| 67 | Martha Amundsen | 46 | Wife | — | Wisconsin |
| 68 | Russell Amundsen | 22 | Son | Asst. Mgr. | Wisconsin |
| 69 | Clara Zwittin | 54 | Head | — | Canada-French |
| 70 | John Zwittin | 17 | Son | — | Wisconsin |
| 71 | Jerome Korenkiewiz | 23 | Lodger | Machinist | Wisconsin |
| 72 | Royal Dermody | 43 | Head | Machinist | Wisconsin |
| 73 | Anna Dermody | 41 | Wife | — | Wisconsin |
| 74 | Richard Dermody | 17 | Son | — | Wisconsin |
| 75 | Kenneth Dermody | 15 | Son | — | Wisconsin |
| 76 | Dorothy Dermody | 6 | Daughter | — | Wisconsin |
| 77 | Joseph Himmelspach | 58 | Head | Pattern Maker | Germany |
| 78 | Minnie Himmelspach | 50 | Wife | — | Wisconsin |
| 79 | Joseph Himmelspach | 26 | Son | Bookkeeper | No. Dakota |
| 80 | Arthur Himmelspach | 24 | Son | Clerk | Wisconsin |
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)