MN
Mary Nichols — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Delaware-County, Pennsylvania
Our Model Tree links this Mary Nichols across the 1930 and 1940 US Censuses in Delaware-County, Pennsylvania (XGBoost, ~Confirmed) — first a daughter (b.~1923), then head of a 12-person household.
Age 17
b. ~1923
Female
Daughter
Born: Maryland
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Delaware-County, Pennsylvania |
| Surname | Nichols |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | C |
| Age | 17 |
| Marital Status | Single |
| Birthplace | Maryland |
| 1935 Residence (City) | Chester |
| 1935 Residence (County) | Delaware |
| Additional Details | |
| Occupation | Housework |
| Class of Worker | 10 |
| Hours Worked | 6 |
| Highest Grade | No 7 |
| 1935 Residence | Same place |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
| Occupation | Housework |
| Township / Ward | Chester |
| Est. Birth Year | ~1923 |
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.
12 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Anna Nichols | Daughter | — | 9 | ~1931 |
| Edna Nichols | Daughter | — | 6 | ~1934 |
| Mary Nichols | Daughter | — | 17 | ~1923 |
| Delores Nichols | Daughter | — | 2 | ~1938 |
| Naomi Nichols | Daughter | — | 2 | ~1938 |
| Beulah Nichols | Daughter | — | 25 | ~1915 |
| Charles Nichols | Head | — | 49 | ~1891 |
| William Nichols | Son | — | 20 | ~1920 |
| Douglas Nichols | Son | — | 11 | ~1929 |
| Calvin Nichols | Son | — | 14 | ~1926 |
| Emerson Nichols | Son | — | 13 | ~1927 |
| Gertrude Nichols | Spouse | — | 46 | ~1894 |
Census Appearances
1930
Delaware, Pennsylvania
Daughter, age 7
Delaware, Pennsylvania · implied b. ~1923 — 12 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Nichols |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 7 |
| Marital Status | Single |
| Birthplace | Maryland |
| Father's Birthplace | Maryland |
| Mother's Birthplace | Maryland |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
1940
Delaware-County, Pennsylvania
Daughter, age 17
Delaware-County, Pennsylvania · implied b. ~1923 — 12 household members
| Surname | Nichols |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | C |
| Age | 17 |
| Marital Status | Single |
| Birthplace | Maryland |
| 1935 Residence (City) | Chester |
| 1935 Residence (County) | Delaware |
| Occupation | Housework |
| Class of Worker | 10 |
| Hours Worked | 6 |
| Highest Grade | No 7 |
| 1935 Residence | Same place |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
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 Nichols across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Nichols
Daughter · 1940 · age 17 · b. ~1923 · Pennsylvania
★ You are viewing this record
Sibling
Anna Nichols
Sibling · 1940 · age 9
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Beulah Nichols
Sibling · 1940 · age 25
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edna Nichols
Sibling · 1940 · age 6
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Calvin Nichols
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Emerson Nichols
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Naomi Nichols
Sibling · 1940 · age 2
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Douglas Nichols
Sibling · 1940 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Delores Nichols
Sibling · 1940 · age 2
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
William Nichols
Sibling · 1940 · age 20
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-t0627-03488-00219)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Willett Jr Crossan | 4 | Son | — | Pennsylvania |
| 42 | George R Crossan | 2 | Son | — | Pennsylvania |
| 43 | Eugene J Crossan | 0 | Son | — | Pennsylvania |
| 44 | Bronislaw Wawrzonkoski | 52 | Head | Bartender | Poland |
| 45 | Bertha Wawrzonkoski | 53 | Wife | Rougher | Poland |
| 46 | Joseph Wawrzonkoski | 29 | Son | Stevedore | Pennsylvania |
| 47 | Jennie Wawrzonkoski | 23 | Daughter | — | New Hampshire |
| 48 | Josephine Wawrzonkoski | 26 | Daughter | Winder | Pennsylvania |
| 49 | Irene Wawrzonkoski | 20 | Daughter | — | Pennsylvania |
| 50 | John Wawrzonkoski | 12 | Son | — | Pennsylvania |
| 51 | Annie Ardes | 43 | Head | — | Pennsylvania |
| 52 | George Ardes | 25 | Son | Boiler Helper | Pennsylvania |
| 53 | Mary Ardes | 22 | Daughter in law | — | Pennsylvania |
| 54 | Mary Ardes | 22 | Daughter | — | Pennsylvania |
| 55 | Margaret Ardes | 19 | Daughter | — | Pennsylvania |
| 56 | Joseph Ardes | 17 | Son | — | Pennsylvania |
| 57 | John Ardes | 14 | Son | — | Pennsylvania |
| 58 | Elizabeth Sweeney | 10 | Daughter | — | Pennsylvania |
| 59 | Mary Ardes | 2 | Granddaughter | — | Pennsylvania |
| 60 | Josiah Gann | 46 | Head | Smelter | Maryland |
| 61 | Mabel B Gann | 46 | Wife | Maid | Pennsylvania |
| 62 | Charles Nichols | 49 | Head | Laborer | Maryland |
| 63 | Gertrude Nichols | 46 | Wife | — | Maryland |
| 64 | Beulah Nichols | 25 | Daughter | — | Maryland |
| 65 | William Nichols | 20 | Son | Cashier | Maryland |
| 66 | Mary Nichols THIS PERSON | 17 | Daughter | Housework | Maryland |
| 67 | Calvin Nichols | 14 | Son | — | Pennsylvania |
| 68 | Emerson Nichols | 13 | Son | — | Pennsylvania |
| 69 | Douglas Nichols | 11 | Son | — | Pennsylvania |
| 70 | Anna Nichols | 9 | Daughter | — | Pennsylvania |
| 71 | Edna Nichols | 6 | Daughter | — | Pennsylvania |
| 72 | Naomi Nichols | 2 | Daughter | — | Pennsylvania |
| 73 | Delores Nichols | 2 | Daughter | — | Pennsylvania |
| 74 | Margaret E Grundy | 65 | Head | — | Pennsylvania |
| 75 | Anna T Moreland | 63 | Head | — | Pennsylvania |
| 76 | Thomas Chappell | 61 | Lodger | — | England |
| 77 | Frank Mchale | 41 | Lodger | News Dealer | England |
| 78 | Harold Stoudte | 35 | Lodger | Mechanic | England |
| 79 | William Mchale | 20 | Lodger | Blacksmith | Pennsylvania |
| 80 | — | 20 | Lodger | Crane Oper | Pennsylvania |
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)