MK
Mary Koch — 1930 US Census Record
Linked across censuses1930 United States Federal Census · San Diego, California
Our Model Tree links this Mary Koch across the 1920 and 1930 US Censuses in San Diego, California (XGBoost, ~Confirmed) — first a spouse (b.~1889), then head of a 6-person household.
Age 41
b. ~1889
Female
Spouse
Born: California
Married
1930 Census Record Details
| Census Year | 1930 |
| Location | San Diego, California |
| Surname | Koch |
| Given Name | Mary M |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 41 |
| Marital Status | Married |
| Birthplace | California |
| Age at First Marriage | 16 |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Indiana |
| Additional Details | |
| Occupation | none |
| Can Read/Write | Yes |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
| Township / Ward | San Diego City |
| Est. Birth Year | ~1889 |
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.
6 people recorded at the same address in the 1930 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Mary Koch | Spouse | — | 41 | ~1889 |
| Sylvia Koch | Daughter | — | 10 | ~1920 |
| Mary Koch | Daughter | — | 15 | ~1915 |
| John Koch | Son | — | 12 | ~1918 |
| Fred Koch | Son | — | 19 | ~1911 |
| Fred Koch | Head | — | 45 | ~1885 |
Census Appearances
1920
San Diego, …
Spouse, age 31
San Diego, California · implied b. ~1889 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Koch |
| Given Name | May M. |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 31 |
| Marital Status | Married |
| Birthplace | California |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Indiana |
| Occupation | none |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | California |
| Birth Country | United States |
| Birthplace (normalized) | california |
1930
San Diego, …
Spouse, age 41
San Diego, California · implied b. ~1889 — 6 household members
| Surname | Koch |
| Given Name | Mary M |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 41 |
| Marital Status | Married |
| Birthplace | California |
| Age at First Marriage | 16 |
| Father's Birthplace | Pennsylvania |
| Mother's Birthplace | Indiana |
| Occupation | none |
| Can Read/Write | Yes |
| 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 Koch across 2 US Census years (1920 and 1930) in San Diego, California, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Koch
Spouse · 1930 · age 41 · b. ~1889 · California
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Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1930 US Federal Census — San Diego, California
Open full size
1930 US Federal Census — San Diego, California
Page Contents
50 people indexed on this census page (ia:1930:californiacensus00reel193:0680)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 51 | William C Wylie | 14 | Son | None | Nevada |
| 52 | Harry Wylie | 10 | Son | None | California |
| 53 | Ralph E Courtright | 26 | Head | Merchant | Kansas |
| 54 | Sadie M Courtright | 21 | Wife | Saleslady | Kansas |
| 55 | Eliza Nichols | 77 | Head | None | Texas |
| 56 | Charles E Gibson | 13 | Grandson | None | California |
| 57 | Antonio Jr Carrillo | 33 | Head | Laborer | Mexico |
| 58 | Juana M Carrillo | 34 | Wife | None | Mexico |
| 59 | Bernice Carrillo | 11 | Daughter | None | Mexico |
| 60 | Claudina Carrillo | 10 | Daughter | None | Mexico |
| 61 | Antonio Carrillo | 3 | Son | None | Mexico |
| 62 | Joe Carrillo | 1 | Son | None | Mexico |
| 63 | Charles Selgrove | 52 | Head | Painter | Indiana |
| 64 | Katherine P Selgrove | 49 | Wife | None | Iowa |
| 65 | Fred S Koch | 45 | Head | Truck Driver | Missouri |
| 66 | Mary M Koch THIS PERSON | 41 | Wife | None | California |
| 67 | Fred S Jr Koch | 19 | Son | Waiter | California |
| 68 | Mary L Koch | 15 | Daughter | None | California |
| 69 | John H Koch | 12 | Son | None | California |
| 70 | Sylvia M Koch | 10 | Daughter | None | California |
| 71 | Isaac Tyrell | 65 | Head | None | Illinois |
| 72 | Marie Miller | 35 | Daughter | Mangler | California |
| 73 | John F Miller | 10 | Son | None | California |
| 74 | Bertha Miller | 42 | Head | Mangler | California |
| 75 | Lois Miller | 9 | Daughter | None | California |
| 76 | Odis Price | 25 | Head | Truck Driver | Illinois |
| 77 | Flora Price | 20 | Wife | Housekeeper | Indiana |
| 78 | Charles A Welsher | 42 | Head | Welder | Pennsylvania |
| 79 | Marie H Welsher | 37 | Wife | None | Pennsylvania |
| 80 | Kathryn J Welsher | 17 | Daughter | None | Pennsylvania |
| 81 | Dorothy A Welsher | 15 | Daughter | None | California |
| 82 | Charles A Welsher | 14 | Son | None | California |
| 83 | Mildred J Welsher | 12 | Daughter | None | California |
| 84 | Richard A Welsher | 9 | Son | None | California |
| 85 | Frank Ibarra | 26 | Head | Truck Driver | Mexico |
| 86 | Adeline Ibarra | 23 | Wife | None | Mexico |
| 87 | Arthur Ibarra | 4 | Son | None | California |
| 88 | Walter Ibarra | 3 | Son | None | California |
| 89 | Jerome Ibarra | 2 | Son | None | California |
| 90 | Paul Burg | 48 | Head | Tailor | Serbia |
| 91 | Ottilie M Burg | 44 | Wife | None | Germany |
| 92 | Eleanor S Burg | 13 | Daughter | None | California |
| 93 | Edith Burg | 11 | Daughter | None | California |
| 94 | Martha Burg | 10 | Daughter | None | California |
| 95 | Carl G Burg | 8 | Son | None | California |
| 96 | William R Sisson | 52 | Head | Motorman | Illinois |
| 97 | Lizzie H Sisson | 53 | Wife | None | Indiana |
| 98 | Robert H Sisson | 17 | Son | None | California |
| 99 | William Worden | 32 | Head | Painter | Illinois |
| 100 | Mary R Worden | 26 | Wife | None | Indiana |
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)