MK
Mary Knapp — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Los-Angeles-County, California
Our Model Tree links this Mary Knapp across the 1920, 1930 and 1940 US Censuses in Los-Angeles-County, California (XGBoost, ~Confirmed) — first a head (b.~1867), then head of a 4-person household.
Age 73
b. ~1867
Female
Head
Born: Missouri
Widowed
1940 Census Record Details
| Census Year | 1940 |
| Location | Los-Angeles-County, California |
| Surname | Knapp |
| Given Name | Mary Frances |
| Relationship to Head | Head |
| Sex | F |
| Color / Race | White |
| Age | 73 |
| Marital Status | Widowed |
| Birthplace | Missouri |
| 1935 Residence (City) | Los Angeles City |
| 1935 Residence (County) | Los Angeles |
| Additional Details | |
| Highest Grade | No 4 |
| 1935 Residence | Calif |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
| Township / Ward | Los Angeles City |
| Est. Birth Year | ~1867 |
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.
4 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Granville Lawless | Other | — | 52 | ~1888 |
| Mary Knapp | Head | — | 73 | ~1867 |
| Irish Lawless | Other | — | 16 | ~1924 |
| Joanne Lawless | Daughter | — | 43 | ~1897 |
Census Appearances
1920
Los Angeles, …
Spouse, age 53
Los Angeles, California · implied b. ~1867 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Knapp |
| Given Name | Mary F. |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 53 |
| Marital Status | Married |
| Birthplace | Missouri |
| Father's Birthplace | Virginia |
| Mother's Birthplace | Ohio |
| Occupation | none |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
1930
Los Angeles, …
Spouse, age 63
Los Angeles, California · implied b. ~1867 — 2 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Knapp |
| Given Name | Mary F |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 63 |
| Marital Status | Married |
| Birthplace | Missouri |
| Age at First Marriage | 22 |
| Father's Birthplace | West Virginia |
| Mother's Birthplace | Ohio |
| Occupation | Artist |
| Class of Worker | OA |
| Can Read/Write | Yes |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
1940
Los-Angeles-County, California
Head, age 73
Los-Angeles-County, California · implied b. ~1867 — 4 household members
| Surname | Knapp |
| Given Name | Mary Frances |
| Relationship to Head | Head |
| Sex | F |
| Color / Race | White |
| Age | 73 |
| Marital Status | Widowed |
| Birthplace | Missouri |
| 1935 Residence (City) | Los Angeles City |
| 1935 Residence (County) | Los Angeles |
| Highest Grade | No 4 |
| 1935 Residence | Calif |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
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 Knapp across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Knapp
Head · 1940 · age 73 · b. ~1867 · California
★ 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 — Los-Angeles-County, California
Open full size
1940 US Federal Census — Los-Angeles-County, California
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00379-00523)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | John B Trujillo | 35 | cousin | Busboy | New Mexico |
| 2 | Josie Trujillo | 34 | wife | Waitress | New Mexico |
| 3 | Rosella Trujillo | 4 | daughter | — | New Mexico |
| 4 | Elfidio Maez | 39 | boarder | Dishwasher | New Mexico |
| 5 | Robel Maestez | 50 | boarder | — | New Mexico |
| 6 | Francisco Galindo | 45 | Head | Salesman | Mexico |
| 7 | Guadalupe Galindo | 40 | wife | — | Mexico |
| 8 | Abelardo Galindo | 16 | son | — | Texas |
| 9 | Hector Galindo | 14 | son | — | Texas |
| 10 | Edwardo Galindo | 13 | son | — | Texas |
| 11 | Patricia Robles | 28 | Head | House Cleaner | California |
| 12 | Chano Mendez | 31 | son in law | Miller | California |
| 13 | Beatrice Mendez | 28 | daughter | — | California |
| 14 | Rosie Mendez | 10 | grand daughter | — | California |
| 15 | Nellie Mendez | 9 | grand daughter | — | California |
| 16 | Robert Mendez | 3 | grand son | — | California |
| 17 | David Mendez | 1 | grand son | — | California |
| 18 | Tranquilino Cano | 37 | Head | Night Porter | Mexico |
| 19 | Manuela Cano | 35 | wife | Nut Sheller | Mexico |
| 20 | Johnnie Cano | 2 | son | — | California |
| 21 | Rose Marie Cano | 0 | daughter | — | California |
| 22 | Lupe Avilla | 23 | brother in law | Night Porter | Mexico |
| 23 | Josephine Avilla | 25 | sister | Nut Sheller | Mexico |
| 24 | Gloria Avilla | 5 | niece | — | California |
| 25 | Lidia Avilla | 3 | niece | — | California |
| 26 | Sarah Beidman | 51 | Head | Manager | Russia |
| 27 | — | None | — | — | — |
| 28 | — | None | — | — | — |
| 29 | Luke Ontiveros | 22 | Head | Bus Boy | Texas |
| 30 | Olga Ontiveros | 22 | wife | — | Mexico |
| 31 | Robert Ontiveros | 0 | son | — | California |
| 32 | Mary Frances Knapp THIS PERSON | 73 | Head | — | Missouri |
| 33 | Granville Lee Lawless | 52 | son in law | Driller | Tennessee |
| 34 | Joanne M. Lawless | 43 | daughter | — | Wisconsin |
| 35 | Irish Lawless | 16 | grand daughter | — | California |
| 36 | Andrew Holquin | 23 | Head | Pantryman | Arizona |
| 37 | Jennie Holquin | 22 | wife | Presser | Mexico |
| 38 | Andre Mariani | 41 | Head | Laborer | Italy |
| 39 | Mary Mariani | 38 | wife | Packer | Italy |
| 40 | Hall Festich | 55 | Head | Proprietor | Yugoslavia |
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)