JL
John Leahy — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Wayne-County, Michigan
Our Model Tree links this John Leahy across the 1930 and 1940 US Censuses in Wayne-County, Michigan (XGBoost, ~Confirmed) — first a son (b.~1919), then head of a 9-person household.
Age 21
b. ~1919
Male
Son
Born: Michigan
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Wayne-County, Michigan |
| Surname | Leahy |
| Given Name | John H. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Michigan |
| 1935 Residence (City) | Detroit |
| 1935 Residence (County) | Wayne |
| Additional Details | |
| Occupation | New worker |
| Hours Worked | 4 |
| Income (1939) | 0 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| Birth State | Michigan |
| Birth Country | United States |
| Birthplace (normalized) | michigan |
| Occupation | New Worker |
| Township / Ward | Detroit |
| Est. Birth Year | ~1919 |
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.
9 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Irene Leahy | Daughter | — | 4 | ~1936 |
| Marie Leahy | Daughter | — | 17 | ~1923 |
| James Leahy | Head | — | 47 | ~1893 |
| Frances Leahy | Daughter | — | 7 | ~1933 |
| Donald Leahy | Son | — | 13 | ~1927 |
| John Leahy | Son | — | 21 | ~1919 |
| Alberta Leahy | Daughter | — | 10 | ~1930 |
| Robert Leahy | Son | — | ~1940 | |
| Laura Leahy | Spouse | — | 53 | ~1887 |
Census Appearances
1930
Wayne, Michigan
Son, age 11
Wayne, Michigan · implied b. ~1919 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Leahy |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Michigan |
| Father's Birthplace | Northern Ireland |
| Mother's Birthplace | Michigan |
| Can Read/Write | Yes |
| Birth State | Michigan |
| Birth Country | United States |
| Birthplace (normalized) | michigan |
1940
Wayne-County, Michigan
Son, age 21
Wayne-County, Michigan · implied b. ~1919 — 9 household members
| Surname | Leahy |
| Given Name | John H. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Michigan |
| 1935 Residence (City) | Detroit |
| 1935 Residence (County) | Wayne |
| Occupation | New worker |
| Hours Worked | 4 |
| Income (1939) | 0 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same place |
| Birth State | Michigan |
| Birth Country | United States |
| Birthplace (normalized) | michigan |
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 Leahy across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Leahy
Son · 1940 · age 21 · b. ~1919 · Michigan
★ You are viewing this record
Sibling
Marie Leahy
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Donald Leahy
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Irene Leahy
Sibling · 1940 · age 4
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Alberta Leahy
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Robert Leahy
Sibling · 1940 · age
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Frances Leahy
Sibling · 1940 · age 7
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 — Wayne-County, Michigan
Open full size
1940 US Federal Census — Wayne-County, Michigan
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01881-00465)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | James Leahy | 47 | Head | Blacksmith | Ireland |
| 42 | Laura Leahy | 53 | Wife | — | Michigan |
| 43 | John H. Leahy THIS PERSON | 21 | Son | New Worker | Michigan |
| 44 | Marie Leahy | 17 | Daughter | — | Michigan |
| 45 | Donald Leahy | 13 | Son | — | Michigan |
| 46 | Alberta Leahy | 10 | Daughter | — | Michigan |
| 47 | Frances Leahy | 7 | Daughter | — | Michigan |
| 48 | Irene Leahy | 4 | Daughter | — | Michigan |
| 49 | Robert Leahy | 0 | Son | — | Michigan |
| 50 | Floyd R. Fenn | 33 | Head | Spot Welder | Ohio |
| 51 | Mary C. Fenn | 33 | Wife | — | Michigan |
| 52 | Mary C. Fenn | 13 | Daughter | — | Michigan |
| 53 | Floyd R. Fenn | 11 | Son | — | Michigan |
| 54 | Mardarie J. Fenn | 8 | Daughter | — | Michigan |
| 55 | Gladys Zanger | 40 | Head | — | Michigan |
| 56 | Elaine Zanger | 17 | Daughter | — | Michigan |
| 57 | Marie Campbell | 22 | Lodger | Waitress | Canada (English) |
| 58 | Beatrice S. Klunge | 54 | Head | — | Ireland |
| 59 | Lauretta Klunge | 23 | Daughter | Telephone Operator | Michigan |
| 60 | Leonard Klunge | 21 | Son | File Clerk | Michigan |
| 61 | Anthony N. Catinia | 46 | Head | Repair In Shop | Italy |
| 62 | Petrina Catinia | 41 | Wife | — | Italy |
| 63 | Salvatore Catinia | 24 | Son | Musician | Michigan |
| 64 | Nickola Catinia | 23 | Son | Musician | Michigan |
| 65 | Andrew H. Zikmund | 45 | Head | Tool & Dye Maker | Bohemia |
| 66 | Jennie Zikmund | 40 | Wife | — | Bohemia |
| 67 | Joseph P. Zikmund | 20 | Son | Plant Police | Pennsylvania |
| 68 | Emil A. Zikmund | 18 | Son | — | Pennsylvania |
| 69 | Caroline M. Zikmund | 14 | Daughter | — | Pennsylvania |
| 70 | William R. Chambers | 24 | Head | Arc Welder | Michigan |
| 71 | Virginia Chambers | 24 | Wife | — | W. Virginia |
| 72 | William R. Chambers | 1 | Son | — | Michigan |
| 73 | Earnest J. Fortune | 37 | Brother-in-law | Laborer | Virginia |
| 74 | Euba Fortune | 27 | Sister-in-law | — | Mississippi |
| 75 | Alfred Nansen | 46 | Head | Elevator Operator | Denmark |
| 76 | Mabel E. Nansen | 39 | Wife | — | Michigan |
| 77 | Marion William Nansen | 46 | Brother | Gear Cutter | Denmark |
| 78 | Frances Gnasik | 43 | Head | Food Checker | Michigan |
| 79 | Agnes Gnasik | 41 | Sister | Sewing Machine Operator | Michigan |
| 80 | Helen Gnasik | 40 | Sister | Time Clerk | Michigan |
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)