JL
John Leonard — 1940 US Census Record
Model Tree available1940 United States Federal Census · Allegheny-County, Pennsylvania
Our Model Tree links this John Leonard across the 1910, 1920, 1930 and 1940 US Censuses in Allegheny-County, Pennsylvania (XGBoost, ~Confirmed), with identified parents Julia & Charles — first a head (b.~1909), then head of a 3-person household.
Age 31
b. ~1909
Male
Head
Born: Pennsylvania
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Allegheny-County, Pennsylvania |
| Surname | Leonard |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 31 |
| Marital Status | Married |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | City of Pittsburgh |
| 1935 Residence (County) | Allegheny |
| Additional Details | |
| Occupation | Mechanic |
| Industry | Air Brake Co. |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 2400 |
| Highest Grade | H-4 |
| 1935 Residence | Same place |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
| Occupation | Mechanic |
| Township / Ward | City Of Pittsburgh |
| Est. Birth Year | ~1909 |
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.
3 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| John Leonard | Head | — | 31 | ~1909 |
| John Leonard | Son | — | 1 | ~1939 |
| Nora Leonard | Spouse | — | 29 | ~1911 |
Census Appearances
1910
Allegheny, Pennsylvania
Son, age 1
Allegheny, Pennsylvania · implied b. ~1909 — 8 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Leonard |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 1 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Occupation | none |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1920
Allegheny, Pennsylvania
Son, age 11
Allegheny, Pennsylvania · implied b. ~1909 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Leonard |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1930
Allegheny, Pennsylvania
Son, age 21
Allegheny, Pennsylvania · implied b. ~1909 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Leonard |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Occupation | Laborer |
| Industry | Steel Mill |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1940
Allegheny-County, Pennsylvania
Head, age 31
Allegheny-County, Pennsylvania · implied b. ~1909 — 3 household members
| Surname | Leonard |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 31 |
| Marital Status | Married |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | City of Pittsburgh |
| 1935 Residence (County) | Allegheny |
| Occupation | Mechanic |
| Industry | Air Brake Co. |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 2400 |
| Highest Grade | H-4 |
| 1935 Residence | Same place |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
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 Leonard across 4 US Census years (1910, 1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: mother Julia Leonard (~0.92 confidence) and father Charles Leonard (~0.92 confidence) and father Charles Leonard (~0.92 confidence) and mother Mary Leonard (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Mother
Julia Leonard
b. ~1866
Source mother
● Household
· direct · ~0.92
Father
Charles Leonard
b. ~1877
Source father
● Household
· direct · ~0.92
Father
Charles Leonard
b. ~1878
Source father
● Household
· direct · ~0.92
Mother
Mary Leonard
b. ~1879
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Leonard
Head · 1940 · age 31 · b. ~1909 · Pennsylvania
★ 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 — Allegheny-County, Pennsylvania
Open full size
1940 US Federal Census — Allegheny-County, Pennsylvania
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03660-00708)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | James Miller | 23 | Head | Laborer | Pennsylvania |
| 2 | Mary Miller | 21 | Wife | — | Pennsylvania |
| 3 | Patricia Miller | 2 | Daughter | — | Pennsylvania |
| 4 | Edward Small | 26 | Head | Laborer | Pennsylvania |
| 5 | Grace Small | 25 | Wife | — | Pennsylvania |
| 6 | Mary K. Small | 2 | Daughter | — | Pennsylvania |
| 7 | Elizabeth L. Small | 0 | Daughter | — | Pennsylvania |
| 8 | George Mochring | 26 | Head | Clerk | West Virginia |
| 9 | Rebecca Mochring | 30 | Wife | Laborer | West Virginia |
| 10 | Charles Mochring | 11 | Son | — | West Virginia |
| 11 | John Coogan | 38 | Head | Draftsman | Pennsylvania |
| 12 | Gertrude Coogan | 35 | Wife | — | Pennsylvania |
| 13 | John Coogan | 12 | Son | — | Pennsylvania |
| 14 | William Coogan | 11 | Son | — | Pennsylvania |
| 15 | James Coogan | 9 | Son | — | Pennsylvania |
| 16 | Gertrude Coogan | 2 | Daughter | — | Pennsylvania |
| 17 | William Quinn | 70 | Father | — | Eire Ireland |
| 18 | Baptiste Quinn | 26 | Daughter | New Worker | Pennsylvania |
| 19 | Frank Boggs | 77 | Head | — | Eire Ireland |
| 20 | Ruth E. Boggs | 36 | Daughter | Teacher | Pennsylvania |
| 21 | William Boggs | 38 | Son | Clerk | Pennsylvania |
| 22 | George Lang | 60 | Head | Inspector | Pennsylvania |
| 23 | Catherine Lang | 45 | Wife | — | Pennsylvania |
| 24 | William Lang | 27 | Son | Clerk | Pennsylvania |
| 25 | Harry L. Lang | 22 | Son | New Worker | Pennsylvania |
| 26 | Fred Kraus | 42 | Lodger | Dyer & Cleaner | Pennsylvania |
| 27 | Harry Kraus | 60 | Lodger | — | Pennsylvania |
| 28 | John Leonard THIS PERSON | 31 | Head | Mechanic | Pennsylvania |
| 29 | Nora Leonard | 29 | Wife | — | Pennsylvania |
| 30 | John Jr. Leonard | 1 | Son | — | Pennsylvania |
| 31 | William Thomas | 31 | Head | Salesman | Pennsylvania |
| 32 | Susan Thomas | 30 | Wife | — | Pennsylvania |
| 33 | William Thomas | 5 | Son | — | Pennsylvania |
| 34 | Johanna Thomas | 3 | Daughter | — | Pennsylvania |
| 35 | Richard Kapp | 34 | Head | Electrician | Pennsylvania |
| 36 | Estella Kapp | 28 | Wife | — | Pennsylvania |
| 37 | Charles Neitsch | 32 | Head | Laborer | Pennsylvania |
| 38 | Mary Neitsch | 21 | Wife | — | Ohio |
| 39 | Walter Strom | 33 | Head | Janitor | Pennsylvania |
| 40 | May Strom | 27 | Wife | — | Pennsylvania |
Pedigree Summary
John
Gen 1 · 4 parents
~0.92
Max depth 4 (1900–1950 window)
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)