WC
William Callahan — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Middlesex-County, Massachusetts
Our Model Tree links this William Callahan across the 1930 and 1940 US Censuses in Middlesex-County, Massachusetts (XGBoost, ~Confirmed) — first a son (b.~1916), then head of a 7-person household.
Age 24
b. ~1916
Male
Son
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Middlesex-County, Massachusetts |
| Surname | Callahan |
| Given Name | William F. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 24 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Somerville City |
| 1935 Residence (County) | Middlesex |
| Additional Details | |
| Occupation | Mail Carrier |
| Industry | Post Office |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 750 |
| Highest Grade | H 4 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Mail Carrier |
| Township / Ward | Somerville City |
| Est. Birth Year | ~1916 |
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.
7 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to William | Age | Birth yr |
|---|---|---|---|---|
| Mary Callahan | Daughter | — | 35 | ~1905 |
| Joseph Callahan | Son | — | 16 | ~1924 |
| Ellen Callahan | Spouse | — | 63 | ~1877 |
| Annie Callahan | Daughter | — | 31 | ~1909 |
| William Callahan | Son | — | 24 | ~1916 |
| Daniel Callahan | Head | — | 68 | ~1872 |
| Daniel Callahan | Son | — | 28 | ~1912 |
Census Appearances
1930
Middlesex, Massachusetts
Son, age 14
Middlesex, Massachusetts · implied b. ~1916 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Callahan |
| Given Name | William |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Middlesex-County, Massachusetts
Son, age 24
Middlesex-County, Massachusetts · implied b. ~1916 — 7 household members
| Surname | Callahan |
| Given Name | William F. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 24 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Somerville City |
| 1935 Residence (County) | Middlesex |
| Occupation | Mail Carrier |
| Industry | Post Office |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 750 |
| 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 Callahan across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
William Callahan
Son · 1940 · age 24 · b. ~1916 · Massachusetts
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Sibling
Daniel Callahan
Sibling · 1940 · age 28
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Mary Callahan
Sibling · 1940 · age 35
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Annie Callahan
Sibling · 1940 · age 31
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Callahan
Sibling · 1940 · age 16
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-t0627-01704-00330)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Mildred Costa | 15 | Daughter | — | Massachusetts |
| 2 | Ruth Costa | 11 | Daughter | — | Massachusetts |
| 3 | Leander Mason | 31 | Head | Landscape | England |
| 4 | Beatrice Mason | 24 | Wife | Clerk | Massachusetts |
| 5 | Albert W. Stynes | 27 | Head | Shipper | Massachusetts |
| 6 | Celia E. Stynes | 24 | Wife | — | Massachusetts |
| 7 | Robert E. Stynes | 5 | Son | — | Massachusetts |
| 8 | Dora B. Dussault | 62 | Head | — | Canada |
| 9 | Herbert P. Wellman | 47 | Head | Office Clerk | Massachusetts |
| 10 | Gertie Wellman | 35 | Wife | — | Scotland |
| 11 | Irene B. Wellman | 12 | Daughter | — | Connecticut |
| 12 | William A. Empey | 37 | Head | Maintenance | Massachusetts |
| 13 | Gertrude M. Empey | 37 | Wife | — | Massachusetts |
| 14 | William A. Jr. Empey | 3 | Son | — | Massachusetts |
| 15 | Edward Barberian | 46 | Head | Insurance Agent | Armenia |
| 16 | Yevnige Barberian | 42 | Wife | — | Armenia |
| 17 | Sara S. Barberian | 21 | Daughter | Candy Packer | Armenia |
| 18 | Annie M. Barberian | 17 | Daughter | — | Massachusetts |
| 19 | George B. Barberian | 13 | Son | — | Massachusetts |
| 20 | Edwina C. Barberian | 11 | Daughter | — | Massachusetts |
| 21 | Thomas F. Moroney | 34 | Head | Clerk | Ireland |
| 22 | Gertrude Moroney | 33 | Wife | — | Massachusetts |
| 23 | Maurice G. Dreyfuss | 48 | Head | Ice Cream Maker | Canada |
| 24 | Katherine D. Dreyfuss | 46 | Wife | — | Maine |
| 25 | Dorothy J. Dreyfuss | 10 | Daughter | — | Massachusetts |
| 26 | James J. Laughlin | 50 | Head | — | Scotland |
| 27 | Robert Laughlin | 20 | Son | Clerk | Philadelphia |
| 28 | George J. Sheehan | 39 | Head | Book Binder | Massachusetts |
| 29 | Margaret M. Sheehan | 39 | Wife | Telephone Operator | Massachusetts |
| 30 | Helen T. Sheehan | 10 | Daughter | — | Massachusetts |
| 31 | Mary F. Sheehan | 9 | Daughter | — | Massachusetts |
| 32 | Elizabeth A. Sheehan | 6 | Daughter | — | Massachusetts |
| 33 | Joseph F. Sheehan | 4 | Son | — | Massachusetts |
| 34 | Daniel F. Callahan | 68 | Head | Switchman | Massachusetts |
| 35 | Ellen T. Callahan | 63 | Wife | — | Ireland |
| 36 | Mary G. Callahan | 35 | Daughter | Clerk | Massachusetts |
| 37 | Annie J. Callahan | 31 | Daughter | Telephone Operator | Massachusetts |
| 38 | Daniel J. Jr. Callahan | 28 | Son | Switchman | Massachusetts |
| 39 | William F. Callahan THIS PERSON | 24 | Son | Mail Carrier | Massachusetts |
| 40 | Joseph C. Callahan | 16 | Son | — | Massachusetts |
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)