WM
William Mcmahon — 1940 US Census Record
Model Tree available1940 United States Federal Census · Kings-County, New York
Our Model Tree links this William Mcmahon across the 1920, 1930 and 1940 US Censuses in Kings-County, New York (XGBoost, ~Confirmed), with identified parents Timothy & Anna — first a head (b.~1893), then head of a 4-person household.
Age 47
b. ~1893
Male
Head
Born: New York
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Kings-County, New York |
| Surname | McMahon |
| Given Name | William J. |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 47 |
| Marital Status | Married |
| Birthplace | New York |
| 1935 Residence (City) | New York City |
| 1935 Residence (County) | Kings |
| Additional Details | |
| Occupation | Policeman |
| Industry | City of N.Y. |
| Class of Worker | GW |
| Hours Worked | 40 |
| Income (1939) | 604 |
| Highest Grade | No 8 |
| 1935 Residence | Same Place |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
| Occupation | Policeman |
| Township / Ward | New York City |
| Est. Birth Year | ~1893 |
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.
4 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to William | Age | Birth yr |
|---|---|---|---|---|
| William Mcmahon | Son | — | 14 | ~1926 |
| Arleen Mcmahon | Daughter | — | 15 | ~1925 |
| William Mcmahon | Head | — | 47 | ~1893 |
| Rose Mcmahon | Spouse | — | 36 | ~1904 |
Census Appearances
1920
Kings, New …
Son, age 27
Kings, New York · implied b. ~1893 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | William J |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Single |
| Birthplace | New York |
| Father's Birthplace | New York |
| Mother's Birthplace | Ireland |
| Occupation | Policeman |
| Class of Worker | W |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
1930
Kings, New …
Head, age 37
Kings, New York · implied b. ~1893 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | William |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 37 |
| Marital Status | Married |
| Birthplace | New York |
| Age at First Marriage | 31 |
| Father's Birthplace | New York |
| Mother's Birthplace | Ireland |
| Occupation | Policeman |
| Industry | Police Dept |
| Class of Worker | W |
| Can Read/Write | Yes |
| Home Owned/Rented | R |
| Home Value / Rent | 55 |
| Radio Set | R |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
1940
Kings-County, New …
Head, age 47
Kings-County, New York · implied b. ~1893 — 4 household members
| Surname | McMahon |
| Given Name | William J. |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 47 |
| Marital Status | Married |
| Birthplace | New York |
| 1935 Residence (City) | New York City |
| 1935 Residence (County) | Kings |
| Occupation | Policeman |
| Industry | City of N.Y. |
| Class of Worker | GW |
| Hours Worked | 40 |
| Income (1939) | 604 |
| Highest Grade | No 8 |
| 1935 Residence | Same Place |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
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 Mcmahon across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Timothy Mcmahon (~0.92 confidence) and mother Anna Mcmahon (~0.92 confidence). The pedigree spans 1 generation with 2 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Timothy Mcmahon
b. ~1872
Source father
● Household
· direct · ~0.92
Mother
Anna Mcmahon
b. ~1874
Source mother
● Household
· direct · ~0.92
This person
Anchor record
William Mcmahon
Head · 1940 · age 47 · b. ~1893 · New York
★ You are viewing this record
Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Kings-County, New York
Open full size
1940 US Federal Census — Kings-County, New York
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-02614-00899)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Rose French | 63 | Head | Cook | Spain |
| 42 | Edward J. French | 45 | Son | Waitman | New York |
| 43 | Dorothy Ray | 34 | Lodger | Copy Holder | Connecticut |
| 44 | Hazel Reilly | 32 | Lodger | Bill Clerk | Connecticut |
| 45 | Lambert Schmidt | 38 | Head | Salesman | New Jersey |
| 46 | Minna D. Schmidt | 38 | Wife | — | Maryland |
| 47 | Lambert Jr. Schmidt | 14 | Son | — | New York |
| 48 | Harry Schmidt | 12 | Son | — | New York |
| 49 | William Schmidt | 11 | Son | — | New York |
| 50 | Walter E. Clarke | 39 | Head | Adjuster | New York |
| 51 | Karen Clarke | 39 | Wife | — | Sweden |
| 52 | Walter E. Jr. Clarke | 20 | Son | — | New York |
| 53 | Marybelle M. Fagan | 40 | Head | Stenographer | New York |
| 54 | Annie M. Fagan | 76 | Mother | — | New York |
| 55 | William J. Meyers | 34 | Head | Stock Clerk | Scotland |
| 56 | Margaret Meyers | 35 | Wife | Waitress | Scotland |
| 57 | Charles D. Summerson | 48 | Head | Accountant | New York |
| 58 | Susan Summerson | 44 | Wife | — | New York |
| 59 | Richard Summerson | 21 | Son | Runner | New York |
| 60 | Ruth Summerson | 16 | Daughter | — | New York |
| 61 | Carl F. Kempf | 39 | Head | Supt | Germany |
| 62 | Ella Kempf | 40 | Wife | — | Germany |
| 63 | Carl F. Kempf | 13 | Son | — | New York |
| 64 | William J. Mcmahon THIS PERSON | 47 | Head | Policeman | New York |
| 65 | Rose G. Mcmahon | 36 | Wife | — | New York |
| 66 | Arleen Mcmahon | 15 | Daughter | — | New York |
| 67 | William Jr. Mcmahon | 14 | Son | — | New York |
| 68 | Alice Fabri | 36 | Head | Nurse | Pennsylvania |
| 69 | Robert Fabri | 3 | Son | — | New York |
| 70 | William J. Condon | 74 | Father | — | Michigan |
| 71 | Mary Condon | 66 | Mother | — | Pennsylvania |
| 72 | Gertrude Brooker | 34 | Head | Operator | New York |
| 73 | Louise Brooker | 73 | Mother | — | New York |
| 74 | Teresa Sylvester | 62 | Aunt | — | New York |
| 75 | William J. Hanley | 44 | Head | Consultant | New York |
| 76 | Edith Hanley | 43 | Wife | Clerk | New York |
| 77 | Alice Hanley | 19 | Daughter | — | New York |
| 78 | Geraldine Hanley | 14 | Daughter | Typist | New York |
| 79 | Blanche Tuernig | 54 | Head | — | Pennsylvania |
| 80 | Albert Tuernig | 22 | Son | Clerk | Pennsylvania |
Related Census Records
Pedigree Summary
William
Gen 1 · 2 parents
~0.92
Max depth 4 (1900–1950 window)
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)