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William Blair — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Allegheny-County, Pennsylvania
Our Model Tree links this William Blair across the 1930 and 1940 US Censuses in Allegheny-County, Pennsylvania (XGBoost, ~Confirmed) — first a son (b.~1925), then head of a 12-person household.
Age 15
b. ~1925
Male
Son
Born: Pennsylvania
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Allegheny-County, Pennsylvania |
| Surname | Blair |
| Given Name | William |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 15 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | Mt. Oliver |
| 1935 Residence (County) | Allegheny |
| Additional Details | |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
| Township / Ward | Mt Oliver |
| Est. Birth Year | ~1925 |
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.
12 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to William | Age | Birth yr |
|---|---|---|---|---|
| Beatrice Blair | Daughter | — | 9 | ~1931 |
| Dolores Blair | Daughter | — | 17 | ~1923 |
| Amelia Blair | Daughter | — | 5 | ~1935 |
| Anna Blair | Daughter | — | 3 | ~1937 |
| Henrietta Blair | Daughter | — | 19 | ~1921 |
| Regina Blair | Daughter | — | 14 | ~1926 |
| Patricia Blair | Daughter | — | 10 | ~1930 |
| Harry Blair | Head | — | 48 | ~1892 |
| William Blair | Son | — | 15 | ~1925 |
| Harry Blair | Son | — | 12 | ~1928 |
| Edward Blair | Son | — | 20 | ~1920 |
| Catherine Blair | Spouse | — | 47 | ~1893 |
Census Appearances
1930
Allegheny, Pennsylvania
Son, age 3
Allegheny, Pennsylvania · implied b. ~1927 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Blair |
| Given Name | William H. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 3 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1940
Allegheny-County, Pennsylvania
Son, age 15
Allegheny-County, Pennsylvania · implied b. ~1925 — 12 household members
| Surname | Blair |
| Given Name | William |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 15 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | Mt. Oliver |
| 1935 Residence (County) | Allegheny |
| Highest Grade | No 8 |
| 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 William Blair across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
William Blair
Son · 1940 · age 15 · b. ~1925 · Pennsylvania
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Sibling
Anna Blair
Sibling · 1940 · age 3
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Amelia Blair
Sibling · 1940 · age 5
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Blair
Sibling · 1940 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Harry Blair
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Dolores Blair
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Patricia Blair
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Henrietta Blair
Sibling · 1940 · age 19
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Beatrice Blair
Sibling · 1940 · age 9
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Regina Blair
Sibling · 1940 · age 14
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-t0627-03412-00135)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Mary Kohl | 25 | Daughter | Rougher | Pennsylvania |
| 2 | Albert Mellinger | 26 | Head | Steel Worker | Pennsylvania |
| 3 | Ruth Mellinger | 21 | Wife | Stenographer | Pennsylvania |
| 4 | Aloysius Beck | 32 | Head | Carpenter | Pennsylvania |
| 5 | Viola Beck | 31 | Wife | — | Pennsylvania |
| 6 | Bartholomew Gardner | 58 | Head | — | Pennsylvania |
| 7 | Mary Gardner | 36 | Daughter | Clerk | Pennsylvania |
| 8 | Mildred Gardner | 27 | Daughter | Clerk | Pennsylvania |
| 9 | Bernard Gardner | 20 | Son | Clerk | Pennsylvania |
| 10 | William Heitman | 29 | Head | Fire Dept | Pennsylvania |
| 11 | Elizabeth Heitman | 31 | Wife | — | Pennsylvania |
| 12 | Elizabeth Heitman | 11 | Daughter | — | Pennsylvania |
| 13 | William Heitman | 9 | Son | — | Pennsylvania |
| 14 | George Heitman | 1 | Son | — | Pennsylvania |
| 15 | John J. Clark | 51 | Head | Inst. Maker | Pennsylvania |
| 16 | Violet Clark | 41 | Wife | — | Pennsylvania |
| 17 | Alvin Clark | 15 | Son | — | Colorado |
| 18 | Betty Lou Clark | 13 | Daughter | — | Pennsylvania |
| 19 | Thelma Clark | 5 | Daughter | — | Pennsylvania |
| 20 | Harry Blair | 48 | Head | Painter | Pennsylvania |
| 21 | Catherine Blair | 47 | Wife | — | Pennsylvania |
| 22 | Edward Blair | 20 | Son | Painter | Pennsylvania |
| 23 | Henrietta Blair | 19 | Daughter | — | Pennsylvania |
| 24 | Dolores Blair | 17 | Daughter | Sorting | Pennsylvania |
| 25 | William Blair THIS PERSON | 15 | Son | — | Pennsylvania |
| 26 | Regina Blair | 14 | Daughter | — | Pennsylvania |
| 27 | Harry Blair | 12 | Son | — | Pennsylvania |
| 28 | Patricia Blair | 10 | Daughter | — | Pennsylvania |
| 29 | Beatrice Blair | 9 | Daughter | — | Pennsylvania |
| 30 | Amelia Blair | 5 | Daughter | — | Pennsylvania |
| 31 | Anna Marie Blair | 3 | Daughter | — | Pennsylvania |
| 32 | Fred Huchick | 44 | Head | Baker | Pennsylvania |
| 33 | Anna Huchick | 44 | Wife | — | Pennsylvania |
| 34 | Fred Huchick | 12 | Son | — | Pennsylvania |
| 35 | Henry Schulte | 72 | Father-in-law | — | Germany |
| 36 | Fred Gerst | 71 | Lodger | — | Pennsylvania |
| 37 | Carl Schumacher | 38 | Head | Draftsman | Pennsylvania |
| 38 | Hazel Schumacher | 38 | Wife | — | Pennsylvania |
| 39 | Carl Jr. Schumacher | 10 | Son | — | Pennsylvania |
| 40 | Richard Schumacher | 6 | Son | — | 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)