JM
John Mack — 1940 US Census Record
Model Tree available1940 United States Federal Census · Montgomery-County, Pennsylvania
Our Model Tree links this John Mack across the 1910, 1920, 1930 and 1940 US Censuses in Montgomery-County, Pennsylvania (XGBoost, ~Confirmed), with identified parents Christiana & Christiana — first a head (b.~1889), then head of a 5-person household.
Age 51
b. ~1889
Male
Head
Born: Pennsylvania
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Montgomery-County, Pennsylvania |
| Surname | Mack |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 51 |
| Marital Status | Married |
| Birthplace | Pennsylvania |
| 1935 Residence (County) | Montgomery |
| Additional Details | |
| Occupation | Farmer |
| Industry | dairy farm |
| Class of Worker | OA |
| Hours Worked | 60 |
| Highest Grade | No 8 |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
| Occupation | Farmer |
| Township / Ward | Lower Salford |
| Est. Birth Year | ~1889 |
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.
5 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Hannah Mack | Daughter | — | 13 | ~1927 |
| Eva Mack | Daughter | — | 20 | ~1920 |
| Elizabeth Mack | Daughter | — | 23 | ~1917 |
| John Mack | Head | — | 51 | ~1889 |
| Emma Mack | Spouse | — | 48 | ~1892 |
Census Appearances
1910
Montgomery, Pennsylvania
Son, age 21
Montgomery, Pennsylvania · implied b. ~1889 — 8 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Mach |
| Given Name | John A. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Occupation | Cigar maker |
| Industry | Factory |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1920
Montgomery, Pennsylvania
Son, age 31
Montgomery, Pennsylvania · implied b. ~1889 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Mack |
| Given Name | John A. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 31 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Occupation | Cigar Maker |
| Industry | Factory |
| Class of Worker | W |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1930
Montgomery, Pennsylvania
Son, age 41
Montgomery, Pennsylvania · implied b. ~1889 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Mack |
| Given Name | John A. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 41 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Occupation | Laborer |
| Industry | Railroad |
| Class of Worker | W |
| Can Read/Write | Yes |
| Veteran | No |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1940
Montgomery-County, Pennsylvania
Head, age 51
Montgomery-County, Pennsylvania · implied b. ~1889 — 5 household members
| Surname | Mack |
| Given Name | John |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 51 |
| Marital Status | Married |
| Birthplace | Pennsylvania |
| 1935 Residence (County) | Montgomery |
| Occupation | Farmer |
| Industry | dairy farm |
| Class of Worker | OA |
| Hours Worked | 60 |
| Highest Grade | No 8 |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
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 Mack across 4 US Census years (1910, 1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: mother Christiana Mack (~0.92 confidence) and mother Christiana Mach (~0.92 confidence) and father John Mack (~0.92 confidence) and father John Mack (~0.92 confidence) and father John Mach (~0.92 confidence). The pedigree spans 1 generation with 5 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Mother
Christiana Mack
b. ~1857
Source mother
● Household
· direct · ~0.92
Mother
Christiana Mach
b. ~1860
Source mother
● Household
· direct · ~0.92
Father
John Mack
b. ~1860
Source father
● Household
· direct · ~0.92
Father
John Mack
b. ~1860
Source father
● Household
· direct · ~0.92
Father
John Mach
b. ~1860
Source father
● Household
· direct · ~0.92
This person
Anchor record
John Mack
Head · 1940 · age 51 · b. ~1889 · Pennsylvania
★ 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 — Montgomery-County, Pennsylvania
Open full size
1940 US Federal Census — Montgomery-County, Pennsylvania
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03581-00210)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Stanley Hendricks | 9 | Son | — | Pennsylvania |
| 42 | Henry G. Swartz | 49 | Head | Farmer | Pennsylvania |
| 43 | Mahala Swartz | 41 | Wife | — | Pennsylvania |
| 44 | Willis Swartz | 17 | Son | Laborer | Pennsylvania |
| 45 | Mildred Swartz | 10 | Daughter | — | Pennsylvania |
| 46 | Mary Ann Ruth | 68 | Mother-in-law | — | Pennsylvania |
| 47 | Rein D. Alderfer | 62 | Head | — | Pennsylvania |
| 48 | Susie Alderfer | 56 | Wife | — | Pennsylvania |
| 49 | Caroline Alderfer | 23 | Daughter | Armhole Feller | Pennsylvania |
| 50 | Naomi Alderfer | 19 | Daughter | Helper | Pennsylvania |
| 51 | Danford Alderfer | 16 | Son | Helper | Pennsylvania |
| 52 | Harold Alderfer | 13 | Son | — | Pennsylvania |
| 53 | Caroline B. Alderfer | 79 | Mother-in-law | — | Pennsylvania |
| 54 | Abram A. Alderfer | 27 | Head | Presser | Pennsylvania |
| 55 | Elizabeth Alderfer | 23 | Wife | Sleeve Feller | Pennsylvania |
| 56 | Lloyd Alderfer | 9 | Son | — | Pennsylvania |
| 57 | Gerald Alderfer | 7 | Son | — | Pennsylvania |
| 58 | Joseph S. Fry | 52 | Head | 60 | Pennsylvania |
| 59 | Estella Fry | 51 | Wife | — | Pennsylvania |
| 60 | Joseph Fry | 24 | Son | — | Pennsylvania |
| 61 | Harold Fry | 18 | Son | New Worker (Time Clerk) | Pennsylvania |
| 62 | Donald Fry | 16 | Son | New Worker (Helper) | Pennsylvania |
| 63 | Lawrence Fry | 13 | Son | — | Pennsylvania |
| 64 | Margaret Fry | 9 | Daughter | — | Pennsylvania |
| 65 | John Mack THIS PERSON | 51 | Head | Farmer | Pennsylvania |
| 66 | Emma Mack | 48 | Wife | — | Pennsylvania |
| 67 | Elizabeth Mack | 23 | Daughter | Dairy Maid | Pennsylvania |
| 68 | Eva Mack | 20 | Daughter | Pocket Sewer | Pennsylvania |
| 69 | Hannah Mack | 13 | Daughter | — | Pennsylvania |
| 70 | Henry S. Mack | 27 | Head | Dairyman | Pennsylvania |
| 71 | Gertrude Mack | 20 | Wife | — | Pennsylvania |
| 72 | Darlene Mack | 2 | Daughter | — | Pennsylvania |
| 73 | Ellis Mack | 29 | Head | Milk Driver | Pennsylvania |
| 74 | Edna S. Mack | 29 | Wife | — | Pennsylvania |
| 75 | Esther Mack | 6 | Daughter | — | Pennsylvania |
| 76 | Ema Jean Mack | 3 | Daughter | — | Pennsylvania |
| 77 | Mary E. Mack | 1 | Daughter | — | Pennsylvania |
| 78 | Harold Hunsberger | 18 | Lodger | 60 | Pennsylvania |
| 79 | Harvey J. Sower | 50 | Head | Carpenter | Pennsylvania |
| 80 | Catherine Sower | 46 | Wife | — | Pennsylvania |
Pedigree Summary
John
Gen 1 · 5 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)