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John Mcgrath — 1940 US Census Record
Model Tree available1940 United States Federal Census · Mercer-County, New Jersey
Our Model Tree links this John Mcgrath across the 1920, 1930 and 1940 US Censuses in Mercer-County, New Jersey (XGBoost, ~Confirmed), with identified parents John & Mary — first a head (b.~1888), then head of a 8-person household.
Age 52
b. ~1888
Male
Head
Born: New Jersey
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Mercer-County, New Jersey |
| Surname | McGrath |
| Given Name | John, Sr. |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 52 |
| Marital Status | Married |
| Birthplace | New Jersey |
| 1935 Residence (City) | Hamilton |
| 1935 Residence (County) | Mercer |
| Additional Details | |
| Occupation | Laborer |
| Industry | Electric & Gas Co. |
| Class of Worker | PW |
| Hours Worked | 5 |
| Income (1939) | 750 |
| Highest Grade | No 5 |
| 1935 Residence | Same place |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
| Occupation | Laborer |
| Township / Ward | Hamilton |
| Est. Birth Year | ~1888 |
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 |
|---|---|---|---|---|
| Anna Mcgrath | Daughter | — | 6 | ~1934 |
| Elizabeth Mcgrath | Daughter | — | 12 | ~1928 |
| Alice Mcgrath | Daughter | — | 9 | ~1931 |
| John Mcgrath | Head | — | 52 | ~1888 |
| John Mcgrath | Son | — | 22 | ~1918 |
| Thomas Mcgrath | Son | — | 17 | ~1923 |
| William Mcgrath | Son | — | 21 | ~1919 |
| Elizabeth Mcgrath | Spouse | — | 48 | ~1892 |
Census Appearances
1920
Mercer, New …
Son, age 32
Mercer, New Jersey · implied b. ~1888 — 16 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McGrath |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 32 |
| Marital Status | Single |
| Birthplace | New Jersey |
| Father's Birthplace | Ireland |
| Mother's Birthplace | New Jersey |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
1930
Mercer, New …
Head, age 42
Mercer, New Jersey · implied b. ~1888 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McGrath |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 42 |
| Marital Status | Married |
| Birthplace | New Jersey |
| Age at First Marriage | 29 |
| Father's Birthplace | Ireland |
| Mother's Birthplace | New Jersey |
| Occupation | Laborer |
| Industry | Steam Railroad |
| Class of Worker | W |
| Can Read/Write | Yes |
| Home Owned/Rented | O |
| Home Value / Rent | 1000 |
| Radio Set | R |
| Birth State | New Jersey |
| Birth Country | United States |
| Birthplace (normalized) | new jersey |
1940
Mercer-County, New …
Head, age 52
Mercer-County, New Jersey · implied b. ~1888 — 8 household members
| Surname | McGrath |
| Given Name | John, Sr. |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 52 |
| Marital Status | Married |
| Birthplace | New Jersey |
| 1935 Residence (City) | Hamilton |
| 1935 Residence (County) | Mercer |
| Occupation | Laborer |
| Industry | Electric & Gas Co. |
| Class of Worker | PW |
| Hours Worked | 5 |
| Income (1939) | 750 |
| Highest Grade | No 5 |
| 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 John Mcgrath across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father John Mcgrath (~0.92 confidence) and mother Mary Mcgrath (~0.92 confidence). The pedigree spans 1 generation with 2 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
John Mcgrath
b. ~1850
Source father
● Household
· direct · ~0.92
Mother
Mary Mcgrath
b. ~1850
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Mcgrath
Head · 1940 · age 52 · b. ~1888 · New Jersey
★ 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 — Mercer-County, New Jersey
Open full size
1940 US Federal Census — Mercer-County, New Jersey
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-02356-01012)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Michael Olynyk | 3 | Head | — | New Jersey |
| 42 | Andrew Olynyk | 50 | Head | Laborer | Poland |
| 43 | Mary Olynyk | 46 | Wife | — | Poland |
| 44 | Peter Olynyk | 24 | Son | — | New Jersey |
| 45 | Michael Olynyk | 20 | Son | — | New Jersey |
| 46 | Walter Olynyk | 18 | Son | Laborer | New Jersey |
| 47 | Joseph Olynyk | 15 | Son | Watchman | New Jersey |
| 48 | Nicholas Olynyk | 13 | Son | — | New Jersey |
| 49 | Helen Olynyk | 12 | Daughter | — | New Jersey |
| 50 | Robert Olynyk | 11 | Son | — | New Jersey |
| 51 | Margaret Olynyk | 10 | Daughter | — | New Jersey |
| 52 | Mary Olynyk | 8 | Daughter | — | New Jersey |
| 53 | Andrew, Jr. Olynyk | 7 | Son | — | New Jersey |
| 54 | Charles Olynyk | 5 | Son | — | New Jersey |
| 55 | Harry Olynyk | 5 | Son | — | New Jersey |
| 56 | William Gaskill | 24 | Head | Laborer | New Jersey |
| 57 | Helen Gaskill | 22 | Wife | — | New Jersey |
| 58 | Helen Gaskill | 2 | Daughter | — | New Jersey |
| 59 | John, Sr. Mcgrath THIS PERSON | 52 | Head | Laborer | New Jersey |
| 60 | Elizabeth Mcgrath | 48 | Wife | — | New Jersey |
| 61 | John, Jr. Mcgrath | 22 | Son | Laborer | New Jersey |
| 62 | William Mcgrath | 21 | Son | Laborer | New Jersey |
| 63 | Thomas Mcgrath | 17 | Son | New Worker | New Jersey |
| 64 | Elizabeth Mcgrath | 12 | Daughter | — | New Jersey |
| 65 | Alice Mcgrath | 9 | Daughter | — | New Jersey |
| 66 | Anna Mcgrath | 6 | Daughter | — | New Jersey |
| 67 | Andrew Planchak | 25 | Head | Laborer | Pennsylvania |
| 68 | Olga Planchak | 22 | Wife | — | New Jersey |
| 69 | Mary Planchak | 0 | Daughter | — | Pennsylvania |
| 70 | Katherine King | 60 | Head | — | Pennsylvania |
| 71 | Albert Madeley | 72 | Lodger | — | England |
| 72 | Joseph Pets | 42 | Head | Prison Officer | New Jersey |
| 73 | Liza Pets | 55 | Wife | — | England |
| 74 | Francis Bittner | 59 | Head | Deliveryman | New Jersey |
| 75 | Gertrude Bittner | 57 | Wife | — | New Jersey |
| 76 | Charles Bittner | 19 | Son | — | New Jersey |
| 77 | John Mason | 35 | Head | Laborer | New Jersey |
| 78 | Caroline Mason | 32 | Wife | — | Pennsylvania |
| 79 | Caroline Mason | 3 | Daughter | — | New Jersey |
| 80 | Joan Mason | 2 | Daughter | — | New Jersey |
Pedigree Summary
John
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)