MK
Mary Knapp — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Delaware-County, Pennsylvania
Our Model Tree links this Mary Knapp across the 1930 and 1940 US Censuses in Delaware-County, Pennsylvania (XGBoost, ~Confirmed) — first a daughter (b.~1926), then head of a 7-person household.
Age 14
b. ~1926
Female
Daughter
Born: Penna
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Delaware-County, Pennsylvania |
| Surname | Knapp |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Penna |
| 1935 Residence (City) | Scranton |
| Additional Details | |
| Highest Grade | No 9 |
| 1935 Residence | Pa |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | penna |
| Township / Ward | Yeadon |
| Est. Birth Year | ~1926 |
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.
7 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Patrick Knapp | Son | — | 9 | ~1931 |
| Sidney Knapp | Son | — | 16 | ~1924 |
| Mary Knapp | Daughter | — | 14 | ~1926 |
| Philomena Knapp | Daughter | — | 6 | ~1934 |
| Charles Knapp | Head | — | 40 | ~1900 |
| Charles Knapp | Son | — | 11 | ~1929 |
| Irene Knapp | Spouse | — | 40 | ~1900 |
Census Appearances
1930
Montgomery, Pennsylvania
Daughter, age 3
Montgomery, Pennsylvania · implied b. ~1927 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Knapp |
| Given Name | Marjorie |
| Relationship to Head | daughter |
| Sex | F |
| Color / Race | White |
| Age | 3 |
| Marital Status | Single |
| Birthplace | Penna |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Occupation | none |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | penna |
1940
Delaware-County, Pennsylvania
Daughter, age 14
Delaware-County, Pennsylvania · implied b. ~1926 — 7 household members
| Surname | Knapp |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Penna |
| 1935 Residence (City) | Scranton |
| Highest Grade | No 9 |
| 1935 Residence | Pa |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | penna |
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 Mary Knapp across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Knapp
Daughter · 1940 · age 14 · b. ~1926 · Pennsylvania
★ You are viewing this record
Sibling
Patrick Knapp
Sibling · 1940 · age 9
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Charles Knapp
Sibling · 1940 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Sidney Knapp
Sibling · 1940 · age 16
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Philomena Knapp
Sibling · 1940 · age 6
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 — Delaware-County, Pennsylvania
Open full size
1940 US Federal Census — Delaware-County, Pennsylvania
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03498-00672)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Morris S. Stelzer | 38 | Head | — | Baden-Baden Germany |
| 42 | Elizabeth Stelzer | 36 | Wife | — | Egg Harbor N.J. |
| 43 | Herbert Stelzer | 5 | Son | — | Penna |
| 44 | Sandra Ann Stelzer | 1 | Daughter | — | Penna |
| 45 | Marguerite Stelzer | 0 | Daughter | — | Penna |
| 46 | Philip Sauer | 38 | Head | Superintendent | Massachusetts |
| 47 | Helene Sauer | 36 | Wife | — | New Hampshire |
| 48 | Philip Jr. Sauer | 4 | Son | — | Connecticut |
| 49 | Antone Perry | 71 | Head | Salesman | Lisbon Portugal |
| 50 | Beatrice Perry | 62 | Wife | — | Ontario Canada |
| 51 | John J. Tomalino | 30 | Head | Salesman | Penna |
| 52 | Irene E. Tomalino | 26 | Wife | — | Penna |
| 53 | Susan L. Tomalino | 1 | Daughter | — | Penna |
| 54 | Joseph E. Roche | 41 | Head | Clerk | Penna |
| 55 | Nora Roche | 41 | Wife | — | Penna |
| 56 | Edmund J. Roche | 11 | Son | — | Penna |
| 57 | Mary Jean Roche | 10 | Daughter | — | Penna |
| 58 | Elizabeth Ann Roche | 5 | Daughter | — | Penna |
| 59 | Raymond Huber | 27 | Head | Machinist | Penna |
| 60 | Catherine Huber | 25 | Wife | — | Penna |
| 61 | Neal Herry | 49 | Head | Roofer | Penna |
| 62 | Florence Herry | 43 | Wife | — | Penna |
| 63 | Charles Knapp | 40 | Head | Engineer | Italy |
| 64 | Irene Knapp | 40 | Wife | — | Italy |
| 65 | Sidney Knapp | 16 | Son | — | Penna |
| 66 | Mary Knapp THIS PERSON | 14 | Daughter | — | Penna |
| 67 | Charles Knapp | 11 | Son | — | Penna |
| 68 | Patrick Knapp | 9 | Son | — | Penna |
| 69 | Philomena Knapp | 6 | Daughter | — | Penna |
| 70 | Joseph Doyle | 37 | Head | Disbursement Clerk | Penna |
| 71 | Hannah D. Doyle | 34 | Wife | — | Penna |
| 72 | Joseph Jr. Doyle | 4 | Son | — | Penna |
| 73 | Gerard Doyle | 1 | Son | — | Penna |
| 74 | Cullen Kathryn Doyle | 37 | Sister | Clerk Sales | Penna |
| 75 | William Wright | 31 | Head | Salesman | Penna |
| 76 | Anna Wright | 30 | Wife | — | Penna |
| 77 | Moreno Alfonso Wright | 13 | Nephew | — | Penna |
| 78 | Frederick Seeberger | 54 | Head | Patent Attorney | Penna |
| 79 | Bertha Seeberger | 53 | Wife | — | Penna |
| 80 | Wm. Lait | 33 | Head | Statistician | Penna |
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)