LJ
Leonard Johnson — 1940 US Census Record
Model Tree available1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Leonard Johnson across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed), with identified parents Axel & Ida — first a head (b.~1915), then head of a 3-person household.
Age 25
b. ~1915
Male
Head
Born: Illinois
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Johnson |
| Given Name | Leonard |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Occupation | Mechanical engineer |
| Industry | Diesel electric service |
| Class of Worker | PW |
| Hours Worked | 44 |
| Income (1939) | 2000 |
| Highest Grade | C 2 |
| 1935 Residence | Illinois |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Occupation | Mechanical Engineer |
| Township / Ward | Oak Park |
| 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.
3 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Leonard | Age | Birth yr |
|---|---|---|---|---|
| Leonard Johnson | Head | — | 25 | ~1915 |
| Wayne Johnson | Son | — | 3 | ~1937 |
| Virginia Johnson | Spouse | — | 23 | ~1917 |
Census Appearances
1920
Cook, Illinois
Son, age 3
Cook, Illinois · implied b. ~1917 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Johnson |
| Given Name | Leonard |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 3 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Sweden |
| Mother's Birthplace | Sweden |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1930
Cook, Illinois
Son, age 14
Cook, Illinois · implied b. ~1916 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Johnson |
| Given Name | Leonard |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Sweden |
| Mother's Birthplace | Sweden |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Cook-County, Illinois
Head, age 25
Cook-County, Illinois · implied b. ~1915 — 3 household members
| Surname | Johnson |
| Given Name | Leonard |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago |
| 1935 Residence (County) | Cook |
| Occupation | Mechanical engineer |
| Industry | Diesel electric service |
| Class of Worker | PW |
| Hours Worked | 44 |
| Income (1939) | 2000 |
| Highest Grade | C 2 |
| 1935 Residence | Illinois |
| 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 Leonard Johnson across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Axel Johnson (~0.92 confidence) and mother Ida Johnson (~0.92 confidence) and father Otto Johnson (~0.92 confidence) and mother Caroline Johnson (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Axel Johnson
b. ~1885
Source father
● Household
· direct · ~0.92
Mother
Ida Johnson
b. ~1885
Source mother
● Household
· direct · ~0.92
Father
Otto Johnson
b. ~1887
Source father
● Household
· direct · ~0.92
Mother
Caroline Johnson
b. ~1889
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Leonard Johnson
Head · 1940 · age 25 · b. ~1915 · 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-t0627-00785-00566)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Oliver Erickson | 33 | Head | Secretary To President | Washington D.C. |
| 2 | Eleanor Erickson | 33 | Wife | — | Illinois |
| 3 | Leopold Kepper | 53 | Head | Janitor | Germany |
| 4 | Sophia Kepper | 58 | Wife | — | Germany |
| 5 | Edward O. Sheehan | 35 | Head | Commercial Manager | Illinois |
| 6 | Leonard Johnson THIS PERSON | 25 | Head | Mechanical Engineer | Illinois |
| 7 | Virginia Johnson | 23 | Wife | — | Illinois |
| 8 | Wayne Johnson | 3 | Son | — | Illinois |
| 9 | John Thomas Brooks | 29 | Head | Salesman | New Jersey |
| 10 | Betty Lee Brooks | 22 | Wife | Receptionist | Michigan |
| 11 | William Wright | 26 | Head | Advertising Manager | Australia |
| 12 | Mary Jane Wright | 25 | Wife | — | Illinois |
| 13 | Lewis J. Komorous | 31 | Head | Assistant Superintendent | Illinois |
| 14 | Mary Joyce Komorous | 23 | Wife | — | Illinois |
| 15 | Joseph Benson | 41 | Head | Broker | Illinois |
| 16 | Eleanor Benson | 39 | Wife | — | Illinois |
| 17 | Anna Weigel | 42 | Head | Bookkeeper | Illinois |
| 18 | Mary Weigel | 40 | Sister | Clerk - Office | Illinois |
| 19 | William Lewis | 27 | Head | Chemical Engineer | Illinois |
| 20 | Lois Lewis | 26 | Wife | — | Illinois |
| 21 | Alphonse De Witte | 53 | Head | Janitor | Belgium |
| 22 | Cesarene De Witte | 50 | Wife | — | Belgium |
| 23 | Mary Louise De Witte | 24 | Daughter | Stenographer | Canada - English |
| 24 | Rosemary De Witte | 22 | Daughter | Typist | Canada - English |
| 25 | Marcel De Witte | 19 | Son | — | Canada - English |
| 26 | Denerie Devenet | 40 | Lodger | Janitor | Holland |
| 27 | Wilbur Dunklee | 45 | Head | Salesman | Indiana |
| 28 | Jessie Dunklee | 39 | Wife | — | Vermont |
| 29 | Barbara Ann Dunklee | 11 | Daughter | — | Illinois |
| 30 | Patricia Ann Dunklee | 1 | Daughter | — | Illinois |
| 31 | Harry L. Gilman | 35 | Head | Assistant Superintendent | Iowa |
| 32 | Orena Gilman | 32 | Wife | — | Missouri |
| 33 | Robert Gilman | 6 | Son | — | Illinois |
| 34 | Joseph T. Barley | 40 | Head | Service Tender | Illinois |
| 35 | Ruth Barley | 36 | Wife | — | Illinois |
| 36 | James Barley | 7 | Son | — | Illinois |
| 37 | Arthur Frey | 41 | Head | Salesman | Illinois |
| 38 | Alice Frey | 40 | Wife | — | Illinois |
| 39 | Mary Alice Frey | 14 | Daughter | — | Illinois |
| 40 | Robert George Frey | 12 | Son | — | Illinois |
Pedigree Summary
Leonard
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)