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Mary Leonard — 1940 US Census Record
Model Tree available1940 United States Federal Census · Suffolk-County, Massachusetts
Our Model Tree links this Mary Leonard across the 1920, 1930 and 1940 US Censuses in Suffolk-County, Massachusetts (XGBoost, ~Confirmed), with identified parents Mary & Martin — first a daughter (b.~1903), then head of a 2-person household.
Age 37
b. ~1903
Female
Daughter
Born: Massachusetts
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Suffolk-County, Massachusetts |
| Surname | Leonard |
| Given Name | Mary A. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 37 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Boston City |
| 1935 Residence (County) | Suffolk |
| Additional Details | |
| Occupation | Bookkeeper |
| Class of Worker | PW |
| Hours Worked | 20 |
| Income (1939) | 727 |
| Highest Grade | H 4 |
| 1935 Residence | Same place |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
| Occupation | Bookkeeper |
| Township / Ward | Boston City |
| Est. Birth Year | ~1903 |
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.
2 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Mary Leonard | Daughter | — | 37 | ~1903 |
| Mary Leonard | Head | — | 89 | ~1851 |
Census Appearances
1920
Suffolk, Massachusetts
Daughter, age 15
Suffolk, Massachusetts · implied b. ~1905 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Leonard |
| Given Name | Mary E |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 15 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Occupation | Student |
| Industry | Elementary |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1930
Suffolk, Massachusetts
Daughter, age 27
Suffolk, Massachusetts · implied b. ~1903 — 11 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Leonard |
| Given Name | Mary A. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 27 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| Father's Birthplace | Massachusetts |
| Mother's Birthplace | Massachusetts |
| Occupation | Telephone Operator |
| Industry | Telephone |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Massachusetts |
| Birth Country | United States |
| Birthplace (normalized) | massachusetts |
1940
Suffolk-County, Massachusetts
Daughter, age 37
Suffolk-County, Massachusetts · implied b. ~1903 — 2 household members
| Surname | Leonard |
| Given Name | Mary A. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 37 |
| Marital Status | Single |
| Birthplace | Massachusetts |
| 1935 Residence (City) | Boston City |
| 1935 Residence (County) | Suffolk |
| Occupation | Bookkeeper |
| Class of Worker | PW |
| Hours Worked | 20 |
| Income (1939) | 727 |
| Highest Grade | H 4 |
| 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 Leonard across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: mother Mary Leonard (~0.92 confidence) and father Martin Leonard (~0.92 confidence) and father Frank Leonard (~0.92 confidence) and mother David Leonard (~0.92 confidence). The pedigree spans 1 generation with 4 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Mother
Mary Leonard
b. ~1851
Source mother
● Household
· direct · ~0.92
Father
Martin Leonard
b. ~1874
Source father
● Household
· direct · ~0.92
Father
Frank Leonard
b. ~1878
Source father
● Household
· direct · ~0.92
Mother
David Leonard
b. ~1879
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Mary Leonard
Daughter · 1940 · age 37 · b. ~1903 · Massachusetts
★ You are viewing this record
Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Suffolk-County, Massachusetts
Open full size
1940 US Federal Census — Suffolk-County, Massachusetts
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01669-00835)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | John Kennedy | 60 | Head | Mechanic | Irish Free State |
| 2 | Charles S. Gay | 65 | Head | Agent | New York |
| 3 | Roberta Gay | 62 | Wife | — | Scotland |
| 4 | Mary Hartstone | 50 | Head | Music Teacher | Massachusetts |
| 5 | Emma Burgess | 78 | Boarder | — | England |
| 6 | Walter Weller | 60 | Lodger | — | Massachusetts |
| 7 | Howard Hennessy | 44 | Head | Policeman | New York |
| 8 | Anne E. Hennessy | 39 | Wife | Waitress | Massachusetts |
| 9 | Madeline Cogan | 15 | Step daughter | — | Massachusetts |
| 10 | William Field | 37 | Head | — | Maine |
| 11 | Mary Field | 85 | Grandmother | — | Maine |
| 12 | Isabell Field | 46 | Aunt | P. B. X. Operator | Maine |
| 13 | Margaret Coyal | 73 | Head | — | Massachusetts |
| 14 | Nelson Dimick | 51 | Lodger | Mechanic | New Hampshire |
| 15 | Frances Glickman | 47 | Head | Store | Russia |
| 16 | Murray E. Glickman | 22 | Son | — | Massachusetts |
| 17 | Herbert W. Glickman | 16 | Daughter | — | Massachusetts |
| 18 | James F. Kelley | 48 | Head | Clerk | Massachusetts |
| 19 | John J. Kelley | 47 | Brother | Laborer | Massachusetts |
| 20 | Mary E. Kelley | 37 | Sister | Operator | Massachusetts |
| 21 | Elizabeth Hines | 77 | Aunt | — | Irish Free State |
| 22 | Katherine Mckinney | 68 | Aunt | — | Irish Free State |
| 23 | Aaron Knowlton | 53 | Head | Operator | Massachusetts |
| 24 | Cora A. Knowlton | 53 | Wife | — | Canada English |
| 25 | Jessie M. Knowlton | 29 | Daughter | Bookkeeper | Massachusetts |
| 26 | Paul Sybertz | 21 | Son-in-law | Clerk | Massachusetts |
| 27 | Lillian T. Sybertz | 20 | Daughter | Salesgirl | Massachusetts |
| 28 | Henry Wipperman | 62 | Head | Stenographer | Massachusetts |
| 29 | Victoria Wipperman | 49 | Sister | — | Massachusetts |
| 30 | Lillian Rivas | 45 | Lodger | — | Massachusetts |
| 31 | Mary Leonard | 89 | Head | — | Irish Free State |
| 32 | Mary A. Leonard THIS PERSON | 37 | Daughter | Bookkeeper | Massachusetts |
| 33 | Thomas Lawlor | 38 | Head | Carpenter | Irish Free State |
| 34 | Margaret D. Lawlor | 39 | Wife | — | Irish Free State |
| 35 | Catherine Lawlor | 9 | Daughter | — | Massachusetts |
| 36 | — | None | — | — | — |
| 37 | John F. Connell | 44 | Head | Stereotyper | Massachusetts |
| 38 | Catherine Connell | 37 | Wife | Sales-Clerk | Massachusetts |
| 39 | John Sullivan | 60 | Head | Operator | Massachusetts |
| 40 | Catherine Sullivan | 54 | Wife | — | Massachusetts |
Pedigree Summary
Mary
Gen 1 · 4 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)