MI
Mary Irwin — 1940 US Census Record
Linked across censuses1940 United States Federal Census · New-Castle-County, Delaware
Our Model Tree links this Mary Irwin across the 1930 and 1940 US Censuses in New-Castle-County, Delaware (XGBoost, ~Confirmed) — first a daughter (b.~1919), then head of a 6-person household.
Age 21
b. ~1919
Female
Daughter
Born: Delaware
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | New-Castle-County, Delaware |
| Surname | Irwin |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Delaware |
| 1935 Residence (City) | Wilmington city |
| 1935 Residence (County) | New Castle |
| Additional Details | |
| Occupation | Social Worker |
| Industry | Welfare |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 500 |
| Highest Grade | Hs 4 |
| 1935 Residence | Delaware |
| Birth State | Delaware |
| Birth Country | United States |
| Birthplace (normalized) | delaware |
| Occupation | Social Worker |
| Township / Ward | Wilmington City |
| Est. Birth Year | ~1919 |
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.
6 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Frances Irwin | Daughter | — | 18 | ~1922 |
| Betty-Anne Irwin | Daughter | — | 13 | ~1927 |
| Marguerite Irwin | Spouse | — | 50 | ~1890 |
| Mary Irwin | Daughter | — | 21 | ~1919 |
| William Irwin | Head | — | 58 | ~1882 |
| Louise Irwin | Daughter | — | 16 | ~1924 |
Census Appearances
1930
New Castle, …
Daughter, age 11
New Castle, Delaware · implied b. ~1919 — 7 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Irwin |
| Given Name | Mary C. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Delaware |
| Father's Birthplace | Delaware |
| Mother's Birthplace | Delaware |
| Can Read/Write | Yes |
| Birth State | Delaware |
| Birth Country | United States |
| Birthplace (normalized) | delaware |
1940
New-Castle-County, Delaware
Daughter, age 21
New-Castle-County, Delaware · implied b. ~1919 — 6 household members
| Surname | Irwin |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 21 |
| Marital Status | Single |
| Birthplace | Delaware |
| 1935 Residence (City) | Wilmington city |
| 1935 Residence (County) | New Castle |
| Occupation | Social Worker |
| Industry | Welfare |
| Class of Worker | PW |
| Hours Worked | 48 |
| Income (1939) | 500 |
| Highest Grade | Hs 4 |
| 1935 Residence | Delaware |
| Birth State | Delaware |
| Birth Country | United States |
| Birthplace (normalized) | delaware |
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 21 · b. ~1919 · Delaware
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Sibling
Frances Irwin
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Betty-Anne Irwin
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Louise Irwin
Sibling · 1940 · age 16
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 — New-Castle-County, Delaware
Open full size
1940 US Federal Census — New-Castle-County, Delaware
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00551-00120)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Lucy V. Monigle | 37 | Wife | — | Delaware |
| 2 | Joseph P. Monigle | 15 | Son | — | Delaware |
| 3 | Donald Monigle | 10 | Son | — | Delaware |
| 4 | Alice Bowman | 57 | Mother-in-law | — | Delaware |
| 5 | Hanes Riggin | 37 | Head | Office Clerk | Delaware |
| 6 | Ruth R. Riggin | 42 | Wife | — | New Jersey |
| 7 | Harry F. Dietz | 47 | Head | Research- | Indiana |
| 8 | Dorothy H. Dietz | 46 | Wife | — | Indiana |
| 9 | William H. Dietz | 19 | Son | — | Indiana |
| 10 | Donald M. Dietz | 17 | Son | — | Indiana |
| 11 | James C. Matthews | 42 | Head | — | Pennsylvania |
| 12 | Mae D. Matthews | 31 | Wife | — | Maryland |
| 13 | William Irwin | 58 | Head | Manager | Delaware |
| 14 | Marguerite Irwin | 50 | Wife | — | New York |
| 15 | Mary Irwin THIS PERSON | 21 | Daughter | Social Worker | Delaware |
| 16 | Frances A. Irwin | 18 | Daughter | — | Delaware |
| 17 | Louise Irwin | 16 | Daughter | — | Delaware |
| 18 | Betty-Anne Irwin | 13 | Daughter | — | Delaware |
| 19 | William M. Bowe | 39 | Head | Electrician | Delaware |
| 20 | Myrtle V. Bowe | 38 | Wife | — | Delaware |
| 21 | William Jr. Bowe | 11 | Son | — | Delaware |
| 22 | Virginia Bowe | 11 | Daughter | — | Delaware |
| 23 | John Wendel Bowe | 8 | Son | — | Delaware |
| 24 | Harry P. Lott | 59 | Father-in-law | — | Delaware |
| 25 | Mettie V. Lott | 55 | Mother-in-law | — | Maryland |
| 26 | James P. Mason | 69 | Head | Foreman | Delaware |
| 27 | Rae A. Mason | 66 | Wife | Teacher | Delaware |
| 28 | Mildred Mason | 42 | Daughter | Teacher | Delaware |
| 29 | Helen Warren Smith | 42 | Head | Teacher | Delaware |
| 30 | Bessie V. Smith | 72 | Mother | — | Delaware |
| 31 | Russell M. Raub | 42 | Lodger | Foreman | Ohio |
| 32 | W. Goers | 42 | Lodger | Salesman | Delaware |
| 33 | Timothy J. Mooney | 56 | Head | — | Delaware |
| 34 | Alice M. Mooney | 51 | Wife | — | Delaware |
| 35 | Mary Mooney | 20 | Daughter | Stenographer | Delaware |
| 36 | Alice Mooney | 18 | Daughter | — | Delaware |
| 37 | Francis Mooney | 16 | Son | — | Delaware |
| 38 | William Mooney | 13 | Son | — | Delaware |
| 39 | Mary A. Haley | 44 | Mother-in-law | — | Pennsylvania |
| 40 | William P. Haley | 46 | Brother-in-law | Street-Cleaner | Delaware |
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)