MM
Mary Monahan — 1930 US Census Record
Linked across censuses1930 United States Federal Census · San Francisco, California
Our Model Tree links this Mary Monahan across the 1930 and 1940 US Censuses in San Francisco, California (XGBoost, ~Confirmed) — first a daughter (b.~1930), then head of a 16-person household.
Age 0
b. ~1930
Female
Daughter
Born: California
Single
1930 Census Record Details
| Census Year | 1930 |
| Location | San Francisco, California |
| Surname | Monahan |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 0 |
| Marital Status | Single |
| Birthplace | California |
| Father's Birthplace | California |
| Mother's Birthplace | California |
| Additional Details | |
| Can Read/Write | Yes |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
| Township / Ward | San Francisco |
| Est. Birth Year | ~1930 |
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.
16 people recorded at the same address in the 1930 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Charles Monahan | Son | — | ~1930 | |
| Francis Monahan | Son | — | ~1930 | |
| Helen Monahan | Spouse | — | 36 | ~1894 |
| George Monahan | Son | — | ~1930 | |
| James Monahan | Head | — | 29 | ~1901 |
| Arthur Monahan | Son | — | ~1930 | |
| Emma Monahan | Spouse | — | 27 | ~1903 |
| William Monahan | Son | — | 1 | ~1929 |
| James Monahan | Son | — | 4 | ~1926 |
| Richard Monahan | Son | — | ~1930 | |
| Joseph Monahan | Son | — | ~1930 | |
| Robert Monahan | Son | — | 2 | ~1928 |
| John Monahan | Son | — | ~1930 | |
| Thomas Monahan | Son | — | ~1930 | |
| Mary Monahan | Daughter | — | ~1930 | |
| Edward Monahan | Son | — | ~1930 |
Census Appearances
1930
San Francisco, …
Daughter, age
San Francisco, California · implied b. ~1930 — 16 household members
| Surname | Monahan |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 0 |
| Marital Status | Single |
| Birthplace | California |
| Father's Birthplace | California |
| Mother's Birthplace | California |
| Can Read/Write | Yes |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
1940
San-Francisco-County, California
Daughter, age 9
San-Francisco-County, California · implied b. ~1931 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Manahan |
| Given Name | Marilyn |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 9 |
| Marital Status | Single |
| Birthplace | California |
| 1935 Residence (City) | San Francisco |
| 1935 Residence (County) | San Francisco |
| Income (1939) | 0 |
| Highest Grade | Yes 3 |
| 1935 Residence | Same Place |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
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 Monahan across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Monahan
Daughter · 1930 · age 0 · b. ~1930 · California
★ You are viewing this record
Sibling
Thomas Monahan
Sibling · 1930 · age
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Monahan
Sibling · 1930 · age
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Robert Monahan
Sibling · 1930 · age 2
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Richard Monahan
Sibling · 1930 · age
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Francis Monahan
Sibling · 1930 · age
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Arthur Monahan
Sibling · 1930 · age
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Charles Monahan
Sibling · 1930 · age
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Monahan
Sibling · 1930 · age
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
James Monahan
Sibling · 1930 · age 4
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
George Monahan
Sibling · 1930 · age
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
William Monahan
Sibling · 1930 · age 1
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Edward Monahan
Sibling · 1930 · age
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
1930 US Federal Census — San Francisco, California
Open full size
1930 US Federal Census — San Francisco, California
Page Contents
50 people indexed on this census page (ia:1930:californiacensus00reel210:0489)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Martha Garrity | 63 | Head | — | California |
| 2 | Sidney Garrity | 31 | Son | Agent | California |
| 3 | John Garrity | 28 | Son | Salesman | California |
| 4 | Lillian Gillespie | 51 | Head | Cashier | Nebraska |
| 5 | Lillian Gillespie | 21 | Daughter | — | Utah |
| 6 | Harry Gillespie | 19 | Son | — | Utah |
| 7 | John Gillespie | 17 | Son | — | Utah |
| 8 | Robert Gillespie | 15 | Son | — | Utah |
| 9 | James Gillespie | 13 | Son | — | Minnesota |
| 10 | William Gillespie | 11 | Son | — | Colorado |
| 11 | George Gillespie | 9 | Son | — | Colorado |
| 12 | Edward Gillespie | 7 | Son | — | Colorado |
| 13 | Frank Gillespie | 5 | Son | — | Colorado |
| 14 | Thomas Gillespie | 3 | Son | — | Colorado |
| 15 | Fred Brown | 71 | Head | Salesman | Missouri |
| 16 | Wallis Anderson | 42 | Head | — | Illinois |
| 17 | Mabel Anderson | 34 | Wife | Stenographer | California |
| 18 | Alice Mabel | 42 | Daughter | Stenographer | California |
| 19 | Alice Mabel | 14 | Daughter | — | California |
| 20 | Alice Mabel | 12 | Daughter | — | California |
| 21 | Alice Mabel | 10 | Daughter | — | California |
| 22 | Alice Mabel | 8 | Daughter | — | California |
| 23 | Alice Mabel | 6 | Daughter | — | California |
| 24 | Arthur Hunt | 60 | Head | Manager | Massachusetts |
| 25 | Mary Hunt | 60 | Wife | Manager | Indiana |
| 26 | Arthur Hunt | 30 | Son | Agent | Indiana |
| 27 | Andrew Whitmore | 42 | Head | Manager | Missouri |
| 28 | Stanley Larson | 33 | Head | Agent | Illinois |
| 29 | Dorothy Larson | 29 | Wife | — | Illinois |
| 30 | Stanley Larson | 12 | Son | — | Illinois |
| 31 | John Patrick | 40 | Head | Inspector | Utah |
| 32 | Madeline Patrick | 36 | Wife | — | Montana |
| 33 | John Patrick | 11 | Son | — | Utah |
| 34 | James Monahan | 29 | Head | Furniture | California |
| 35 | Emma Monahan | 27 | Wife | — | California |
| 36 | James Monahan | 4 | Son | — | California |
| 37 | Robert Monahan | 2 | Son | — | California |
| 38 | William Monahan | 1 | Son | — | California |
| 39 | Mary Monahan THIS PERSON | 0 | Daughter | — | California |
| 40 | John Monahan | 0 | Son | — | California |
| 41 | Thomas Monahan | 0 | Son | — | California |
| 42 | Edward Monahan | 0 | Son | — | California |
| 43 | Francis Monahan | 0 | Son | — | California |
| 44 | Joseph Monahan | 0 | Son | — | California |
| 45 | George Monahan | 0 | Son | — | California |
| 46 | Charles Monahan | 0 | Son | — | California |
| 47 | Richard Monahan | 0 | Son | — | California |
| 48 | Arthur Monahan | 0 | Son | — | California |
| 49 | Helen Monahan | 36 | Wife | — | Massachusetts |
| 50 | Lottie Monahan | 75 | Head | Performer | Louisiana |
About This Record & Model Tree
This record was independently indexed by YourRoots from the 1930 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)