JL
John Leonard — 1940 US Census Record
Model Tree available1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this John Leonard across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed), with identified parents Patrick & Pauline — first a head (b.~1906), then head of a 5-person household.
Age 34
b. ~1906
Male
Head
Born: Illinois
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Leonard |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 34 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Occupation | Telephone Repairman |
| Industry | Telephone Co. |
| Class of Worker | PW |
| Hours Worked | 40 |
| Highest Grade | H-2 |
| 1935 Residence | Same Place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Occupation | Telephone Repairman |
| Township / Ward | Chicago |
| Est. Birth Year | ~1906 |
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.
5 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Dolores Leonard | Daughter | — | 8 | ~1932 |
| John Leonard | Head | — | 34 | ~1906 |
| John Leonard | Son | — | 6 | ~1934 |
| Thomas Leonard | Son | — | 2 | ~1938 |
| Beatrice Leonard | Spouse | — | 29 | ~1911 |
Census Appearances
1920
Cook, Illinois
Son, age 14
Cook, Illinois · implied b. ~1906 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Leonard |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Ireland |
| Mother's Birthplace | Wisconsin |
| Occupation | none |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1930
Cook, Illinois
Son, age 25
Cook, Illinois · implied b. ~1905 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Leonard |
| Given Name | John |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Ireland |
| Mother's Birthplace | Ireland |
| Occupation | Steam fitter |
| Industry | Building trades |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Head, age 34
Cook-County, Illinois · implied b. ~1906 — 5 household members
| Surname | Leonard |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 34 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Occupation | Telephone Repairman |
| Industry | Telephone Co. |
| Class of Worker | PW |
| Hours Worked | 40 |
| Highest Grade | H-2 |
| 1935 Residence | Same Place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
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 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Patrick Leonard (~0.92 confidence) and mother Pauline Leonard (~0.92 confidence). The pedigree spans 1 generation with 2 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Patrick Leonard
b. ~1870
Source father
● Household
· direct · ~0.92
Mother
Pauline Leonard
b. ~1878
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Leonard
Head · 1940 · age 34 · b. ~1906 · Illinois
★ 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 — Cook-County, Illinois
Open full size
1940 US Federal Census — Cook-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00965-00020)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Jack Pullman | 23 | Head | Sales Clerk | Illinois |
| 42 | Vera Pullman | 18 | Daughter | — | Illinois |
| 43 | Gloria Pullman | 8 | Daughter | — | Illinois |
| 44 | Ben Bendersky | 64 | Lodger | — | Russia |
| 45 | Josephine Zielinski | 19 | Lodger | Servant | Illinois |
| 46 | John Murphy | 70 | Head | — | Kansas |
| 47 | Charles E. Long | 61 | Brother | — | Illinois |
| 48 | Pearl Long | 49 | Sister | — | Illinois |
| 49 | Emil Sauperans | 17 | Niece | — | Illinois |
| 50 | Ralph Bloch | 32 | Head | Sales Clerk | Lithuania |
| 51 | Chaye Bloch | 70 | Mother | — | Lithuania |
| 52 | Isaac Deutsch | 65 | Lodger | — | Russia |
| 53 | James Murphy | 36 | Head | Chauffeur | Illinois |
| 54 | Marie Murphy | 31 | Wife | — | Illinois |
| 55 | James Murphy | 7 | Son | — | Illinois |
| 56 | Louis Karp | 51 | Head | Owner | Russia |
| 57 | Lizzie Karp | 46 | Wife | — | Russia |
| 58 | Agnes Karp | 28 | Daughter | Stenographer | Connecticut |
| 59 | Ruth Karp | 21 | Daughter | Stenographer | Illinois |
| 60 | David Karp | 15 | Son | — | Illinois |
| 61 | Charles Karp | 14 | Son | — | Illinois |
| 62 | Elaine Berman-Wagner | 40 | Head | Sales Clerk | Czechoslovakia |
| 63 | Henry Berman-Wagner | 4 | Son | — | Illinois |
| 64 | Elmer Hupka | 48 | Head | — | Illinois |
| 65 | Lillian Hupka | 48 | Wife | — | Illinois |
| 66 | Anna Lertock | 58 | Head | — | Czechoslovakia |
| 67 | Albie Lertock | 38 | Daughter | Stenographer | Illinois |
| 68 | Rose Lertock | 32 | Daughter | — | Illinois |
| 69 | John Leonard THIS PERSON | 34 | Head | Telephone Repairman | Illinois |
| 70 | Beatrice Leonard | 29 | Wife | — | Illinois |
| 71 | Dolores Leonard | 8 | Daughter | — | Illinois |
| 72 | John Jr. Leonard | 6 | Son | — | Illinois |
| 73 | Thomas Leonard | 2 | Son | — | Illinois |
| 74 | Rose Leiman | 38 | Head | — | Illinois |
| 75 | George Leiman | 17 | Son | — | Illinois |
| 76 | Louise Kertisun | 20 | Head | Practical Nurse | Wisconsin |
| 77 | Mary Mcdonald | 21 | Lodger | Practical Nurse | Wisconsin |
| 78 | Edna La Claire | 20 | Lodger | Practical Nurse | Wisconsin |
| 79 | Fred Laszowski | 57 | Head | Machine Operator | Poland |
| 80 | Henry Laszowski | 23 | Son | Filler | Illinois |
Pedigree Summary
John
Gen 1 · 2 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)