JM
James Mcmahon — 1940 US Census Record
Model Tree available1940 United States Federal Census · Hudson-County, New Jersey
Our Model Tree links this James Mcmahon across the 1920, 1930 and 1940 US Censuses in Hudson-County, New Jersey (XGBoost, ~Confirmed), with identified parents J & James — first a son (b.~1915), then head of a 9-person household.
Age 25
b. ~1915
Male
Son
Born: New Jersey
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Hudson-County, New Jersey |
| Surname | McMahon |
| Given Name | James |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | New Jersey |
| 1935 Residence (City) | City of Bayonne |
| 1935 Residence (County) | Hudson |
| Additional Details | |
| Occupation | Teacher |
| Industry | Public School |
| Class of Worker | GW |
| Hours Worked | 35 |
| Income (1939) | 1400 |
| Highest Grade | H 4 |
| 1935 Residence | Same place |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
| Occupation | Teacher |
| Township / Ward | City Of Bayonne |
| 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.
9 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to James | Age | Birth yr |
|---|---|---|---|---|
| Margaret Mcmahon | Daughter | — | 12 | ~1928 |
| Anna Mcmahon | Daughter | — | 30 | ~1910 |
| Margaret Mcmahon | Head | — | 50 | ~1890 |
| Edward Mcmahon | Son | — | 22 | ~1918 |
| James Mcmahon | Son | — | 25 | ~1915 |
| Joseph Mcmahon | Son | — | 14 | ~1926 |
| William Mcmahon | Son | — | 12 | ~1928 |
| John Mcmahon | Son | — | 24 | ~1916 |
| Henry Mcmahon | Son | — | 20 | ~1920 |
Census Appearances
1920
Hudson, New …
Son, age 5
Hudson, New Jersey · implied b. ~1915 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | James |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 5 |
| Marital Status | Single |
| Birthplace | New Jersey |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Connecticut |
| Occupation | none |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
1930
Hudson, New …
Son, age 15
Hudson, New Jersey · implied b. ~1915 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | James Jr. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 15 |
| Marital Status | Single |
| Birthplace | New Jersey |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Connecticut |
| Can Read/Write | Yes |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
1940
Hudson-County, New …
Son, age 25
Hudson-County, New Jersey · implied b. ~1915 — 9 household members
| Surname | McMahon |
| Given Name | James |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 25 |
| Marital Status | Single |
| Birthplace | New Jersey |
| 1935 Residence (City) | City of Bayonne |
| 1935 Residence (County) | Hudson |
| Occupation | Teacher |
| Industry | Public School |
| Class of Worker | GW |
| Hours Worked | 35 |
| Income (1939) | 1400 |
| Highest Grade | H 4 |
| 1935 Residence | Same place |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
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 James Mcmahon across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father J Mcmahon (~0.92 confidence) and father James Mcmahon (~0.92 confidence) and mother Julia Mcmahon (~0.92 confidence) and mother Margaret Mcmahon (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
J Mcmahon
b. ~1873
Source father
● Household
· direct · ~0.92
Father
James Mcmahon
b. ~1873
Source father
● Household
· direct · ~0.92
Mother
Julia Mcmahon
b. ~1876
Source mother
● Household
· direct · ~0.92
Mother
Margaret Mcmahon
b. ~1890
Source mother
● Household
· direct · ~0.92
This person
Anchor record
James Mcmahon
Son · 1940 · age 25 · b. ~1915 · New Jersey
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Sibling
Anna Mcmahon
Sibling · 1940 · age 30
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
William Mcmahon
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Margaret Mcmahon
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Mcmahon
Sibling · 1940 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Mcmahon
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Mcmahon
Sibling · 1940 · age 24
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Henry Mcmahon
Sibling · 1940 · age 20
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 — Hudson-County, New Jersey
Open full size
1940 US Federal Census — Hudson-County, New Jersey
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-02344-00524)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Dennis Murnane | 71 | Head | — | Ireland |
| 2 | Catherine Murnane | 68 | Wife | — | Ireland |
| 3 | Eugene Murnane | 39 | Son | Clerk | New Jersey |
| 4 | Donald Murnane | 39 | Son | Salesman | New Jersey |
| 5 | Mary Murnane | 30 | Daughter | Saleslady | New Jersey |
| 6 | Michael Gallagher | 51 | Head | Machinist | Pennsylvania |
| 7 | Helen Gallagher | 52 | Wife | — | Pennsylvania |
| 8 | Bessie Nolan | 50 | Head | Packer | New Jersey |
| 9 | Ellen Nolan | 50 | Sister | — | New Jersey |
| 10 | James O'Donnell | 73 | Head | — | New Jersey |
| 11 | Joseph O'Donnell | 35 | Son | Patrolman | New Jersey |
| 12 | Marie O'Donnell | 31 | Daughter | Teacher | New Jersey |
| 13 | Hugh O'Donnell | 29 | Son | Laborer | New Jersey |
| 14 | Sally O'Connell | 40 | Daughter | — | New Jersey |
| 15 | Daniel Daniel | 39 | Son-in-law | Clerk | New Jersey |
| 16 | Daniel Daniel | 2 | Grandson | — | New Jersey |
| 17 | Daniel J. Noonan | 55 | Head | Watchman | Ireland |
| 18 | Mary Noonan | 55 | Wife | — | Ireland |
| 19 | Mary V. Noonan | 23 | Daughter | Telephonist | New Jersey |
| 20 | Martin O'Flaherty | 40 | Head | Pipe Fitter | New Jersey |
| 21 | Catherine O'Flaherty | 39 | Wife | — | New Jersey |
| 22 | Mary O'Flaherty | 11 | Daughter | — | New Jersey |
| 23 | Catherine O'Flaherty | 8 | Daughter | — | New Jersey |
| 24 | Jeremiah Shanahan | 67 | Head | — | Ireland |
| 25 | Mary Shanahan | 67 | Wife | — | Ireland |
| 26 | George Brahim | 45 | Head | Printer | New York |
| 27 | Anna Brahim | 41 | Wife | — | New Jersey |
| 28 | Anna Brahim | 15 | Daughter | — | New Jersey |
| 29 | Howard Brahim | 11 | Son | — | New Jersey |
| 30 | Henry May | 39 | Head | Pipe Fitter | New Jersey |
| 31 | Caroline May | 49 | Sister | — | New York |
| 32 | Margaret Mcmahon | 50 | Head | — | New Jersey |
| 33 | Anna Mcmahon | 30 | Daughter | Clerk | New Jersey |
| 34 | James Mcmahon THIS PERSON | 25 | Son | Teacher | New Jersey |
| 35 | John Mcmahon | 24 | Son | Clerk | New Jersey |
| 36 | Edward Mcmahon | 22 | Son | Pantryman | New Jersey |
| 37 | Henry Mcmahon | 20 | Son | Laborer | New Jersey |
| 38 | William Mcmahon | 12 | Son | — | New Jersey |
| 39 | Joseph Mcmahon | 14 | Son | — | New Jersey |
| 40 | Margaret Mcmahon | 12 | Daughter | — | New Jersey |
Related Census Records
Pedigree Summary
James + 7 siblings
Gen 1 · 4 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)