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John Leach — 1940 US Census Record
Linked across censuses1940 United States Federal Census · St.-Louis-County, Missouri
Our Model Tree links this John Leach across the 1930 and 1940 US Censuses in St.-Louis-County, Missouri (XGBoost, ~Confirmed) — first a son (b.~1925), then head of a 6-person household.
Age 15
b. ~1925
Male
Son
Born: Missouri
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | St.-Louis-County, Missouri |
| Surname | Leach |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 15 |
| Marital Status | Single |
| Birthplace | Missouri |
| 1935 Residence (City) | St. Louis |
| 1935 Residence (County) | St. Louis |
| Additional Details | |
| Income (1939) | 0 |
| Highest Grade | H-1 |
| 1935 Residence | Missouri |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
| Township / Ward | Luxemburg |
| Est. Birth Year | ~1925 |
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 |
|---|---|---|---|---|
| James Leach | Son | — | 10 | ~1930 |
| John Leach | Son | — | 15 | ~1925 |
| Leon Leach | Head | — | 42 | ~1898 |
| Mary Leach | Daughter | — | 13 | ~1927 |
| Helen Leach | Spouse | — | 42 | ~1898 |
| Robert Leach | Son | — | 5 | ~1935 |
Census Appearances
1930
St Louis, …
Son, age 5
St Louis, Missouri · implied b. ~1925 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Lecchi |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 5 |
| Marital Status | Single |
| Birthplace | Missouri |
| Father's Birthplace | Missouri |
| Mother's Birthplace | Missouri |
| Occupation | none |
| Can Read/Write | No |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
1940
St.-Louis-County, Missouri
Son, age 15
St.-Louis-County, Missouri · implied b. ~1925 — 6 household members
| Surname | Leach |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 15 |
| Marital Status | Single |
| Birthplace | Missouri |
| 1935 Residence (City) | St. Louis |
| 1935 Residence (County) | St. Louis |
| Income (1939) | 0 |
| Highest Grade | H-1 |
| 1935 Residence | Missouri |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
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 15 · b. ~1925 · Missouri
★ You are viewing this record
Sibling
Robert Leach
Sibling · 1940 · age 5
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
James Leach
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Mary Leach
Sibling · 1940 · age 13
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 — St.-Louis-County, Missouri
Open full size
1940 US Federal Census — St.-Louis-County, Missouri
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-02151-00245)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Edna R. Dietz | 39 | Wife | — | Missouri |
| 42 | Charles B. Jr. Dietz | 16 | Son | — | Missouri |
| 43 | Herman J. Kempen | 33 | Head | Foreman | Missouri |
| 44 | Mabel Kempen | 27 | Wife | Floor Lady | Missouri |
| 45 | Shirley J. Kempen | 2 | Daughter | — | Missouri |
| 46 | Gertrude Stevens | 48 | Mother-in-law | — | Missouri |
| 47 | Roger G. Korsedgen | 33 | Head | Commercial Artist | Missouri |
| 48 | Marion Korsedgen | 29 | Wife | — | Missouri |
| 49 | Dorothy Korsedgen | 5 | Daughter | — | Missouri |
| 50 | Frank Knussmann | 40 | Head | Department Manager | Missouri |
| 51 | Annabell Knussmann | 40 | Wife | — | Missouri |
| 52 | Anna Knepper | 66 | Mother-in-law | — | England |
| 53 | Richard S. Washburn | 30 | Head | Salesman | Illinois |
| 54 | Robina E. Washburn | 30 | Wife | Nurse | Illinois |
| 55 | Soren C. Christensen | 53 | Head | Steam-Fitter | Denmark |
| 56 | Janetta Christensen | 35 | Wife | — | Missouri |
| 57 | Edward Martin | 18 | Son | — | Missouri |
| 58 | Albert H. Brason | 23 | Head | Dresscutter | Missouri |
| 59 | Inez M. Brason | 25 | Wife | — | Missouri |
| 60 | Marilyn Brason | 2 | Daughter | — | Missouri |
| 61 | Cecilia Hartung | 37 | Sister-in-law | — | Illinois |
| 62 | Carl E. Gebhardt | 33 | Head | Welder | Missouri |
| 63 | Beatrice Gebhardt | 32 | Wife | — | Missouri |
| 64 | Glenn E. Gebhardt | 5 | Son | — | Missouri |
| 65 | Carl S. Swinburne | 33 | Head | Chef | Texas |
| 66 | Eileen Swinburne | 30 | Wife | — | Kansas |
| 67 | Carl G. Jr. Swinburne | 8 | Son | — | Missouri |
| 68 | John W. Trust | 34 | Head | Mechanical Designer | Missouri |
| 69 | Mildred M. Trust | 32 | Wife | — | Arkansas |
| 70 | Jan M. Trust | 5 | Daughter | — | Missouri |
| 71 | John W. Jr. Trust | 2 | Son | — | Missouri |
| 72 | Joan J. Trust | 1 | Daughter | — | Missouri |
| 73 | Leon D. Leach | 42 | Head | Attorney At-Law | Illinois |
| 74 | Helen Leach | 42 | Wife | — | Illinois |
| 75 | John Leach THIS PERSON | 15 | Son | — | Missouri |
| 76 | Mary M. Leach | 13 | Daughter | — | Missouri |
| 77 | James C. Leach | 10 | Son | — | Missouri |
| 78 | Robert Leach | 5 | Son | — | Missouri |
| 79 | James L. Derr | 33 | Head | Assistant | Missouri |
| 80 | Evelyne M. Derr | 26 | Wife | — | Massachusetts |
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)