MI
Mary Irwin — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Washington-County, Pennsylvania
Our Model Tree links this Mary Irwin across the 1930 and 1940 US Censuses in Washington-County, Pennsylvania (XGBoost, ~Confirmed) — first a daughter (b.~1929), then head of a 5-person household.
Age 11
b. ~1929
Female
Daughter
Born: Pennsylvania
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Washington-County, Pennsylvania |
| Surname | Irwin |
| Given Name | Mary Lou |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | Fallowfield Twp. |
| Additional Details | |
| Highest Grade | No 6 |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
| Township / Ward | Fallowfield Twp |
| Est. Birth Year | ~1929 |
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 Mary | Age | Birth yr |
|---|---|---|---|---|
| Margaret Irwin | Daughter | — | 8 | ~1932 |
| Benjamin Irwin | Head | — | 34 | ~1906 |
| Sarah Irwin | Daughter | — | 10 | ~1930 |
| Mary Irwin | Daughter | — | 11 | ~1929 |
| Mary Irwin | Spouse | — | 37 | ~1903 |
Census Appearances
1930
Washington, Pennsylvania
Daughter, age 1
Washington, Pennsylvania · implied b. ~1929 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Irwin |
| Given Name | Mary L. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 1 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Pennsylvania |
| Birth State | Pennsylvania |
| Birth Country | United States |
| Birthplace (normalized) | pennsylvania |
1940
Washington-County, Pennsylvania
Daughter, age 11
Washington-County, Pennsylvania · implied b. ~1929 — 5 household members
| Surname | Irwin |
| Given Name | Mary Lou |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Pennsylvania |
| 1935 Residence (City) | Fallowfield Twp. |
| Highest Grade | No 6 |
| 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 Mary Irwin across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Irwin
Daughter · 1940 · age 11 · b. ~1929 · Pennsylvania
★ You are viewing this record
Sibling
Sarah Irwin
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Margaret Irwin
Sibling · 1940 · age 8
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 — Washington-County, Pennsylvania
Open full size
1940 US Federal Census — Washington-County, Pennsylvania
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03623-00517)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Joanne Williams | 1 | Daughter | — | Pennsylvania |
| 42 | Marie F. Ancarne | 21 | Daughter | Operator | Pennsylvania |
| 43 | Gomer H. Williams | 25 | Head | Machine Operator | Pennsylvania |
| 44 | Leah Williams | 22 | Wife | — | Pennsylvania |
| 45 | Donna June Williams | 3 | Daughter | — | Pennsylvania |
| 46 | Doris Jean Williams | 2 | Daughter | — | Pennsylvania |
| 47 | Matilda Schaffer | 69 | Sister-in-law | — | Pennsylvania |
| 48 | John D. Williams | 66 | Head | — | Pennsylvania |
| 49 | Grace J. Williams | 56 | Wife | — | Pennsylvania |
| 50 | John Lambert | 29 | Head | Miner | Pennsylvania |
| 51 | Margaret Lambert | 29 | Wife | — | Pennsylvania |
| 52 | Virgil Williams | 23 | Head | Miner | Pennsylvania |
| 53 | Viola Williams | 29 | Sister | — | Pennsylvania |
| 54 | John Bachkey | 44 | Head | Laborer | Czechoslovakia |
| 55 | Mary Bachkey | 41 | Wife | — | Pennsylvania |
| 56 | Mike Bachkey | 22 | Son | Laborer | Pennsylvania |
| 57 | Frank Bachkey | 19 | Son | Laborer | Pennsylvania |
| 58 | Ann Dorothy Bachkey | 15 | Daughter | — | Pennsylvania |
| 59 | Mary Ellen Bachkey | 12 | Daughter | — | Pennsylvania |
| 60 | William P. Irwin | 31 | Head | Farm | Pennsylvania |
| 61 | Benjamin B. Irwin | 34 | Head | Farm | Pennsylvania |
| 62 | Mary Irwin | 37 | Wife | — | Pennsylvania |
| 63 | Mary Lou Irwin THIS PERSON | 11 | Daughter | — | Pennsylvania |
| 64 | Sarah Irwin | 10 | Daughter | — | Pennsylvania |
| 65 | Margaret Irwin | 8 | Daughter | — | Pennsylvania |
| 66 | Victor Herman | 30 | Head | Mine | Pennsylvania |
| 67 | Stella Herman | 29 | Wife | — | Pennsylvania |
| 68 | Theodore Herman | 4 | Son | — | Pennsylvania |
| 69 | Clyde Herman | 3 | Son | — | Pennsylvania |
| 70 | Walter A. Herman | 2 | Son | — | Pennsylvania |
| 71 | Howard Hess | 47 | Head | Contracting | Pennsylvania |
| 72 | Vera Hess | 41 | Wife | — | Pennsylvania |
| 73 | George Anna Hess | 6 | Daughter | — | Pennsylvania |
| 74 | Harry Hickman | 64 | Head | Farm | England |
| 75 | Beatrice Hickman | 26 | Daughter | — | Pennsylvania |
| 76 | Charles Herman | 29 | Head | Carpenter | Pennsylvania |
| 77 | Carol Herman | 24 | Wife | — | Pennsylvania |
| 78 | Charles Jr. Herman | 4 | Son | — | Pennsylvania |
| 79 | Earl Herman | 3 | Son | — | Pennsylvania |
| 80 | William Herman | 2 | Son | — | Pennsylvania |
Related Census Records
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)