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William Blair — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Middlesex-County, Massachusetts
Our Model Tree links this William Blair across the 1930 and 1940 US Censuses in Middlesex-County, Massachusetts (XGBoost, ~Confirmed) — first a son (b.~1915), then head of a 10-person household.
Age 25
b. ~1915
Male
Son
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Middlesex-County, Massachusetts |
| Surname | Blair |
| Given Name | William J |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Malden city |
| 1935 Residence (County) | Middlesex |
| Additional Details | |
| Occupation | Mechanic |
| Industry | Machine Shop |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 160 |
| Highest Grade | H-4 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Mechanic |
| Township / Ward | Malden City |
| 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.
10 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to William | Age | Birth yr |
|---|---|---|---|---|
| Dorothy Blair | Daughter | — | 20 | ~1920 |
| Mildred Blair | Daughter | — | 16 | ~1924 |
| William Blair | Head | — | 48 | ~1892 |
| Wilfred Blair | Son | — | 24 | ~1916 |
| Robert Blair | Son | — | 22 | ~1918 |
| Albert Blair | Son | — | 17 | ~1923 |
| William Blair | Son | — | 25 | ~1915 |
| Donald Blair | Son | — | 21 | ~1919 |
| Edmund Blair | Son | — | 15 | ~1925 |
| Mary Blair | Spouse | — | 47 | ~1893 |
Census Appearances
1930
Middlesex, Massachusetts
Son, age 13
Middlesex, Massachusetts · implied b. ~1917 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Blair |
| Given Name | William G. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Naturalization Status | Naturalized |
| Year of Immigration | 1921 |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Canada English |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Middlesex-County, Massachusetts
Son, age 25
Middlesex-County, Massachusetts · implied b. ~1915 — 10 household members
| Surname | Blair |
| Given Name | William J |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Malden city |
| 1935 Residence (County) | Middlesex |
| Occupation | Mechanic |
| Industry | Machine Shop |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 160 |
| Highest Grade | H-4 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
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 25 · b. ~1915 · Massachusetts
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Sibling
Wilfred Blair
Sibling · 1940 · age 24
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Dorothy Blair
Sibling · 1940 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Robert Blair
Sibling · 1940 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Donald Blair
Sibling · 1940 · age 21
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Mildred Blair
Sibling · 1940 · age 16
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Albert Blair
Sibling · 1940 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edmund Blair
Sibling · 1940 · age 15
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 — Middlesex-County, Massachusetts
Open full size
1940 US Federal Census — Middlesex-County, Massachusetts
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01608-00412)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | William W Todd | 27 | Head | Painter | Massachusetts |
| 42 | Joseph Mahoney | 34 | Head | Painter | Canada-English |
| 43 | Edith Mahoney | 30 | Wife | — | Massachusetts |
| 44 | June Mahoney | 10 | Daughter | — | Massachusetts |
| 45 | Paul Mahoney | 9 | Son | — | Massachusetts |
| 46 | Francis J Moriarty | 30 | Head | Salesman-Master | Massachusetts |
| 47 | Hazel L Moriarty | 27 | Wife | — | Massachusetts |
| 48 | Geraldine Moriarty | 2 | Daughter | — | Massachusetts |
| 49 | Carol A Moriarty | 1 | Daughter | — | Massachusetts |
| 50 | Sidney T Brown | 47 | Head | Book-Examiner | Massachusetts |
| 51 | Nellie E Brown | 47 | Wife | — | Massachusetts |
| 52 | Shirley G Brown | 15 | Daughter | — | Massachusetts |
| 53 | Marilyn A Brown | 12 | Daughter | — | Massachusetts |
| 54 | Foster M Brown | 15 | Brother | — | Maine |
| 55 | William E Blair | 48 | Head | Pipe-Fitter | Massachusetts |
| 56 | Mary S Blair | 47 | Wife | — | Massachusetts |
| 57 | William J Blair THIS PERSON | 25 | Son | Mechanic | Massachusetts |
| 58 | Wilfred J Blair | 24 | Son | Painter | Massachusetts |
| 59 | Robert H Blair | 22 | Son | Sheet Metal | Massachusetts |
| 60 | Dorothy G Blair | 20 | Daughter | New Worker | Massachusetts |
| 61 | Donald J Blair | 21 | Son | New Worker | Massachusetts |
| 62 | Albert L Blair | 17 | Son | New Worker | Massachusetts |
| 63 | Mildred J Blair | 16 | Daughter | — | Massachusetts |
| 64 | Edmund Blair | 15 | Son | — | Massachusetts |
| 65 | Jeremiah Foley | 67 | Head | Shipper | Canada-English |
| 66 | Gertrude Foley | 60 | Wife | — | Massachusetts |
| 67 | John Foley | 29 | Son | Clerk-Store | Massachusetts |
| 68 | Fred Foley | 25 | Son | Messenger | Massachusetts |
| 69 | John Foley | 5 | Grand Son | — | Massachusetts |
| 70 | Fred T Carnes | 44 | Head | Sub-Clerk | Massachusetts |
| 71 | Grace M Carnes | 41 | Wife | — | Massachusetts |
| 72 | Fred T Jr Carnes | 12 | Son | — | Massachusetts |
| 73 | Eleanor M Carnes | 10 | Daughter | — | Massachusetts |
| 74 | Thomas F Desmond | 60 | Head | Clerk | Massachusetts |
| 75 | Catherine F Desmond | 58 | Wife | Office Work | Massachusetts |
| 76 | M. Christine Desmond | 25 | Daughter | — | Massachusetts |
| 77 | Robert J Desmond | 22 | Son | Temp Sub | Massachusetts |
| 78 | Virginia M Desmond | 17 | Daughter | Office Clerk | Massachusetts |
| 79 | Richard J Desmond | 16 | Son | — | Massachusetts |
| 80 | Arthur O'Neil | 46 | Boarder | Cab Driver | Massachusetts |
Related Census Records
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)