MC
Mary Carroll — 1940 US Census Record
Model Tree available1940 United States Federal Census · Middlesex-County, Massachusetts
Our Model Tree links this Mary Carroll across the 1920, 1930 and 1940 US Censuses in Middlesex-County, Massachusetts (XGBoost, ~Confirmed), with identified parents Franklin & Henrietta — first a daughter (b.~1916), then head of a 8-person household.
Age 24
b. ~1916
Female
Daughter
Born: Massachusetts
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Middlesex-County, Massachusetts |
| Surname | Carroll |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 24 |
| Marital Status | Married |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Ayer town |
| 1935 Residence (County) | Middlesex |
| Additional Details | |
| Occupation | Domestic |
| Industry | Private Family |
| Class of Worker | PW |
| Hours Worked | 60 |
| Income (1939) | 284 |
| Highest Grade | Hs 3 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Domestic |
| Township / Ward | Ayer Town |
| Est. Birth Year | ~1916 |
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.
8 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Edith Grant | Daughter | — | 18 | ~1922 |
| Mary Carroll | Daughter | — | 24 | ~1916 |
| Patricia Grant | Daughter | — | 15 | ~1925 |
| Florence Grant | Daughter | — | 20 | ~1920 |
| Franklin Grant | Head | — | 62 | ~1878 |
| Doris Carroll | Other | — | 3 | ~1937 |
| Herbert Grant | Son | — | 26 | ~1914 |
| Henrietta Grant | Spouse | — | 59 | ~1881 |
Census Appearances
1920
Middlesex, Massachusetts
Other, age 1
Middlesex, Massachusetts · implied b. ~1919 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Carroll |
| Given Name | Mary |
| Relationship to Head | Granddaughter |
| Sex | F |
| Color / Race | White |
| Age | 1 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1930
Middlesex, Massachusetts
Other, age 12
Middlesex, Massachusetts · implied b. ~1918 — 11 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Carroll |
| Given Name | Mary E. |
| Relationship to Head | Granddaughter |
| Sex | F |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Middlesex-County, Massachusetts
Daughter, age 24
Middlesex-County, Massachusetts · implied b. ~1916 — 8 household members
| Surname | Carroll |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 24 |
| Marital Status | Married |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Ayer town |
| 1935 Residence (County) | Middlesex |
| Occupation | Domestic |
| Industry | Private Family |
| Class of Worker | PW |
| Hours Worked | 60 |
| Income (1939) | 284 |
| Highest Grade | Hs 3 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
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 Carroll across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Franklin Grant (~0.92 confidence) and mother Henrietta Grant (~0.92 confidence). The pedigree spans 1 generation with 2 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Franklin Grant
b. ~1878
Source father
● Household
· direct · ~0.92
Mother
Henrietta Grant
b. ~1881
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Mary Carroll
Daughter · 1940 · age 24 · b. ~1916 · Massachusetts
★ You are viewing this record
Sibling
Patricia Grant
Sibling · 1940 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Herbert Grant
Sibling · 1940 · age 26
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edith Grant
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Florence Grant
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 — Middlesex-County, Massachusetts
Open full size
1940 US Federal Census — Middlesex-County, Massachusetts
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01602-00375)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Blanche M. Thompson | 51 | Head | — | Canada English |
| 2 | Millard Fleet | 77 | Lodger | Carpenter | Canada English |
| 3 | Stanley Fleet | 39 | Lodger | Orchard Helper | Massachusetts |
| 4 | Nellie Murphy | 72 | Head | — | Massachusetts |
| 5 | Margaret Mccarthy | 50 | Niece | Clerk/Typist | Massachusetts |
| 6 | Alice Mccarthy | 44 | Niece | Teacher | Massachusetts |
| 7 | Harry King | 57 | Lodger | Storekeeper | Connecticut |
| 8 | John D. O'Connell | 45 | Head | Clerical | Ohio |
| 9 | Ruth O'Connell | 44 | Wife | — | Washington D.C. |
| 10 | John D. O'Connell | 19 | Son | — | Washington D.C. |
| 11 | Marjorie R. O'Connell | 17 | Daughter | — | Washington D.C. |
| 12 | James O'Connell | 15 | Son | — | Washington D.C. |
| 13 | Patricia O'Connell | 9 | Daughter | — | Hawaii |
| 14 | Elmer E. Hinckley | 78 | Head | Attendant/Dishw. | New Hampshire |
| 15 | Ella G. Hinckley | 77 | Wife | — | Canada English |
| 16 | Cora M. Taft | 51 | Head | — | Massachusetts |
| 17 | Benjamin Taft | 21 | Son | Clerical | Massachusetts |
| 18 | Henry Farnum | 61 | Head | Time Treasurer | New Hampshire |
| 19 | Alice Farnum | 62 | Wife | — | Massachusetts |
| 20 | Nellie M. Whitney | 79 | Head | — | New Hampshire |
| 21 | Katherine Smith | 42 | Head | — | Germany |
| 22 | Margaret Smith | 18 | Daughter | Domestic Serv. | Germany |
| 23 | Gertrude Smith | 15 | Daughter | — | Maine |
| 24 | John Fitzgerald | 49 | Head | Clerk | Irish Free State |
| 25 | Hannah Fitzgerald | 57 | Sister | — | Irish Free State |
| 26 | Franklin Grant | 62 | Head | Photo Finisher | Massachusetts |
| 27 | Henrietta Grant | 59 | Wife | Salesman | New York |
| 28 | Herbert Grant | 26 | Son | Merchant | Massachusetts |
| 29 | Florence Grant | 20 | Daughter | Domestic | Massachusetts |
| 30 | Edith Grant | 18 | Daughter | Clerical | Massachusetts |
| 31 | Patricia Grant | 15 | Daughter | — | Massachusetts |
| 32 | Mary Carroll THIS PERSON | 24 | Daughter | Domestic | Massachusetts |
| 33 | Doris Carroll | 3 | Granddaughter | — | Massachusetts |
| 34 | Hillman Parker | 34 | Head | Electrician | Massachusetts |
| 35 | Lucy M. Parker | 33 | Wife | — | England |
| 36 | Hillman E. Parker | 12 | Son | — | Massachusetts |
| 37 | Barbara Parker | 8 | Daughter | — | Massachusetts |
| 38 | Alma Prokop | 25 | Head | — | Vermont |
| 39 | Lucile Prokop | 7 | Daughter | — | Massachusetts |
| 40 | Harriet Lapointe | 77 | Head | — | Massachusetts |
Pedigree Summary
Mary + 4 siblings
Gen 1 · 2 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)