JI
John Irwin — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Allegheny-County, Pennsylvania
Our Model Tree links this John Irwin across the 1930 and 1940 US Censuses in Allegheny-County, Pennsylvania (XGBoost, ~Confirmed) — first a son (b.~1929), then head of a 5-person household.
Age 11
b. ~1929
Male
Son
Born: Pennsylvania
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Allegheny-County, Pennsylvania |
| Surname | Irwin |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | Pittsburgh |
| 1935 Residence (County) | Allegheny |
| Additional Details | |
| Highest Grade | No 6 |
| 1935 Residence | Same place |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
| Township / Ward | Pittsburgh |
| Est. Birth Year | ~1929 |
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 |
|---|---|---|---|---|
| John Irwin | Son | — | 11 | ~1929 |
| James Irwin | Son | — | 20 | ~1920 |
| John Irwin | Head | — | 42 | ~1898 |
| Margaret Irwin | Spouse | — | 40 | ~1900 |
| William Irwin | Son | — | 7 | ~1933 |
Census Appearances
1930
Allegheny, Pennsylvania
Son, age 1
Allegheny, Pennsylvania · implied b. ~1929 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Irwin |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 1 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Age at First Marriage | 1 |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Can Read/Write | Yes |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1940
Allegheny-County, Pennsylvania
Son, age 11
Allegheny-County, Pennsylvania · implied b. ~1929 — 5 household members
| Surname | Irwin |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | Pittsburgh |
| 1935 Residence (County) | Allegheny |
| Highest Grade | No 6 |
| 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 Irwin across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Irwin
Son · 1940 · age 11 · b. ~1929 · Pennsylvania
★ You are viewing this record
Sibling
James Irwin
Sibling · 1940 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
William Irwin
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 — 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-t0627-03676-00104)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Gertrude Holt | 46 | Wife | — | Pennsylvania |
| 2 | Walter S Holt | 17 | Son | — | Pennsylvania |
| 3 | Theodore H Holt | 15 | Son | — | Pennsylvania |
| 4 | — | None | — | — | — |
| 5 | Albert Kayser | 51 | Head | Floor Man | Nebraska |
| 6 | Albert Jr. Kayser | 27 | Son | Elect Clerk | Pennsylvania |
| 7 | Benjamin Bretch | 77 | Uncle | — | Ohio |
| 8 | Harry R Horton | 50 | Head | Chiropractor | Pennsylvania |
| 9 | Bessie Horton | 46 | Wife | Stenographer | Pennsylvania |
| 10 | Bertha Stover | 40 | Head | — | Pennsylvania |
| 11 | Jeannette Stover | 35 | Daughter | Asst Librarian | Pennsylvania |
| 12 | Andrew Larsen | 72 | Head | — | Scotland |
| 13 | Lucy Larsen | 65 | Wife | — | Ohio |
| 14 | Mary Mctavern | 32 | Daughter | Bookkeeper | Pennsylvania |
| 15 | Frank Mckerver | 61 | Head | Pressman | Mass |
| 16 | Mary E Mckerver | 27 | Daughter | — | Pennsylvania |
| 17 | Francis Mckerver | 24 | Son | Truck Helper | Pennsylvania |
| 18 | Robert Mckerver | 21 | Son | Artist | Pennsylvania |
| 19 | Patricia Mckerver | 20 | Daughter | — | Pennsylvania |
| 20 | John J Irwin | 42 | Head | Accountant | Pennsylvania |
| 21 | Margaret F Irwin | 40 | Wife | — | Pennsylvania |
| 22 | James R Irwin | 20 | Son | Timekeeper | Pennsylvania |
| 23 | John Irwin THIS PERSON | 11 | Son | — | Pennsylvania |
| 24 | William Irwin | 7 | Son | — | Pennsylvania |
| 25 | Edward S. Donohue | 39 | Head | Bookkeeper | Pennsylvania |
| 26 | Helen P Donohue | 40 | Wife | — | Pennsylvania |
| 27 | Regis Donohue | 18 | Son | — | Pennsylvania |
| 28 | Mary Helen Donohue | 8 | Daughter | — | Pennsylvania |
| 29 | Charles Snyder | 30 | Head | Accountant Clerk | Pennsylvania |
| 30 | Margaret J Snyder | 27 | Wife | — | Pennsylvania |
| 31 | Barbara Ann Snyder | 1 | Daughter | — | Pennsylvania |
| 32 | John Greenawalt | 71 | Head | — | Pennsylvania |
| 33 | Bessie Smith | 33 | Daughter | — | Pennsylvania |
| 34 | Frank E Smith | 7 | Grandson | — | Pennsylvania |
| 35 | Robert Smith | 6 | Grandson | — | Pennsylvania |
| 36 | Edward L Jones | 56 | Head | Policeman | Pennsylvania |
| 37 | Theresa Jones | 46 | Wife | — | Ill |
| 38 | Anna M Burger | 69 | Mother-in-law | — | Pennsylvania |
| 39 | Mary Ann Burger | 45 | Daughter | — | Pennsylvania |
| 40 | John J Treiber | 25 | Head | Fireman | Pennsylvania |
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)