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John Monahan — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Norfolk-County, Massachusetts
Our Model Tree links this John Monahan across the 1930 and 1940 US Censuses in Norfolk-County, Massachusetts (XGBoost, ~Confirmed) — first a son (b.~1913), then head of a 8-person household.
Age 27
b. ~1913
Male
Son
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Norfolk-County, Massachusetts |
| Surname | Monahan |
| Given Name | John |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Brookline |
| 1935 Residence (County) | Norfolk |
| Additional Details | |
| Occupation | chiropractor |
| Industry | private practice |
| Class of Worker | OA |
| Hours Worked | 30 |
| Income (1939) | 520 |
| Highest Grade | C 2 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Chiropractor |
| Township / Ward | Brookline |
| Est. Birth Year | ~1913 |
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.
8 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Mary Monahan | Spouse | — | 60 | ~1880 |
| James Collins | Other | — | 40 | ~1900 |
| John Monahan | Son | — | 27 | ~1913 |
| Catherine Collins | Daughter | — | 30 | ~1910 |
| Joseph Monahan | Son | — | 17 | ~1923 |
| John Monahan | Head | — | 65 | ~1875 |
| Mary Collins | Daughter | — | 5 | ~1935 |
| Leo Monahan | Son | — | 23 | ~1917 |
Census Appearances
1930
Suffolk, Massachusetts
Son, age 16
Suffolk, Massachusetts · implied b. ~1914 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Monahan |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 16 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Irish Free State |
| Mother's Birthplace | Irish Free State |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Norfolk-County, Massachusetts
Son, age 27
Norfolk-County, Massachusetts · implied b. ~1913 — 8 household members
| Surname | Monahan |
| Given Name | John |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Brookline |
| 1935 Residence (County) | Norfolk |
| Occupation | chiropractor |
| Industry | private practice |
| Class of Worker | OA |
| Hours Worked | 30 |
| Income (1939) | 520 |
| Highest Grade | C 2 |
| 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 John Monahan across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
John Monahan
Son · 1940 · age 27 · b. ~1913 · Massachusetts
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Sibling
Leo Monahan
Sibling · 1940 · age 23
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Mary Collins
Sibling · 1940 · age 5
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Catherine Collins
Sibling · 1940 · age 30
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Monahan
Sibling · 1940 · age 17
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 — Norfolk-County, Massachusetts
Open full size
1940 US Federal Census — Norfolk-County, Massachusetts
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01626-00373)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Theresa Ullian | 36 | wife | — | Massachusetts |
| 2 | Barbara Ullian | 13 | daughter | — | Massachusetts |
| 3 | Barnett Ullian | 8 | son | — | Massachusetts |
| 4 | Hazel Wood | 22 | servant | Domestic | Canada English |
| 5 | Berthol Stern | 36 | head | Executive | Massachusetts |
| 6 | Gladys Stern | 32 | wife | — | Massachusetts |
| 7 | Berthol Stern | 8 | son | — | Massachusetts |
| 8 | Louis Stern | 4 | son | — | Massachusetts |
| 9 | Sally Mcinnis | 21 | servant | Cook | Newfoundland |
| 10 | Mary Glynn | 25 | servant | Maid | Massachusetts |
| 11 | Thomas R. Welch | 43 | head | Treasurer | Massachusetts |
| 12 | Mary Welch | 32 | wife | — | Massachusetts |
| 13 | Thomas R. Jr. Welch | 4 | son | — | Massachusetts |
| 14 | Mary F. Welch | 4 | daughter | — | Massachusetts |
| 15 | Nancy Welch | 1 | daughter | — | Massachusetts |
| 16 | Edith Raymond | 21 | servant | Housemaid | Massachusetts |
| 17 | John A. Monahan | 65 | head | Inspector | Massachusetts |
| 18 | Mary M. Monahan | 60 | wife | — | Canada English |
| 19 | John Monahan THIS PERSON | 27 | son | Chiropractor | Massachusetts |
| 20 | Leo Monahan | 23 | son | Dealer | Massachusetts |
| 21 | Joseph Monahan | 17 | son | — | Massachusetts |
| 22 | James Collins | 40 | son-in-law | Bond Inspector | Massachusetts |
| 23 | Catherine Collins | 30 | daughter | — | Massachusetts |
| 24 | Mary Jean Collins | 5 | daughter | — | Massachusetts |
| 25 | Theodore S. Williams | 41 | head | Engineer | Massachusetts |
| 26 | Marion Williams | 43 | wife | — | Massachusetts |
| 27 | Stanwood R. Williams | 12 | son | — | Massachusetts |
| 28 | Charles R. Williams | 8 | son | — | Massachusetts |
| 29 | David R. Williams | 5 | son | — | Massachusetts |
| 30 | Theodore R. Williams | 2 | son | — | Massachusetts |
| 31 | Charles A. Levis | 45 | head | Inspector | Massachusetts |
| 32 | Margaret Levis | 37 | wife | — | Massachusetts |
| 33 | Muriel Levis | 12 | daughter | — | Massachusetts |
| 34 | Margaret A. Levis | 8 | daughter | — | Massachusetts |
| 35 | Charles A. Jr. Levis | 7 | son | — | Massachusetts |
| 36 | Joyce Levis | 5 | daughter | — | Massachusetts |
| 37 | Alexander A. Roberts | 77 | father | — | England |
| 38 | Mary Roberts | 82 | aunt | — | England |
| 39 | Harry R. Saffel | 49 | head | Operator | Massachusetts |
| 40 | Ellen L. Saffel | 46 | wife | Director | New York |
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)