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Mary Larsen — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Lake-County, South Dakota
Our Model Tree links this Mary Larsen across the 1930 and 1940 US Censuses in Lake-County, South Dakota (XGBoost, ~Confirmed) — first a spouse (b.~1888), then head of a 9-person household.
Age 52
b. ~1888
Female
Spouse
Born: Iowa
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Lake-County, South Dakota |
| Surname | Larsen |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 52 |
| Marital Status | Married |
| Birthplace | Iowa |
| 1935 Residence (City) | Wentworth Township |
| 1935 Residence (County) | Lake |
| Additional Details | |
| Occupation | Farm Laborer |
| Industry | Farm |
| Class of Worker | NP |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Occupation | Farm Laborer |
| Township / Ward | Wentworth Township |
| Est. Birth Year | ~1888 |
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.
9 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Alvin Larsen | Son | — | 26 | ~1914 |
| Elmer Larsen | Son | — | 18 | ~1922 |
| Carl Larsen | Son | — | 14 | ~1926 |
| Mary Larsen | Spouse | — | 52 | ~1888 |
| Edna Larsen | Daughter | — | 20 | ~1920 |
| Eugene Larsen | Son | — | 12 | ~1928 |
| A Larsen | Head | — | 60 | ~1880 |
| Thelma Larsen | Daughter | — | 16 | ~1924 |
| Phyllis Larsen | Daughter | — | 12 | ~1928 |
Census Appearances
1930
Lake, South …
Spouse, age 42
Lake, South Dakota · implied b. ~1888 — 15 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Larsen |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 42 |
| Marital Status | Married |
| Birthplace | Iowa |
| Age at First Marriage | 20 |
| Father's Birthplace | Denmark |
| Mother's Birthplace | Denmark |
| Can Read/Write | Yes |
| Home Owned/Rented | H |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Lake-County, South …
Spouse, age 52
Lake-County, South Dakota · implied b. ~1888 — 9 household members
| Surname | Larsen |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 52 |
| Marital Status | Married |
| Birthplace | Iowa |
| 1935 Residence (City) | Wentworth Township |
| 1935 Residence (County) | Lake |
| Occupation | Farm Laborer |
| Industry | Farm |
| Class of Worker | NP |
| Highest Grade | No 8 |
| 1935 Residence | Same place |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
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 Larsen across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
Mary Larsen
Spouse · 1940 · age 52 · b. ~1888 · South Dakota
★ 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 — Lake-County, South Dakota
Open full size
1940 US Federal Census — Lake-County, South Dakota
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03859-00835)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Albert Gruenhagen | 43 | Head | Farmer | S. Dak. |
| 2 | Clara Gruenhagen | 37 | Wife | — | Illinois |
| 3 | Eugene Gruenhagen | 17 | Son | Carpenter | S. Dak. |
| 4 | Leland Gruenhagen | 1 | Son | — | S. Dak. |
| 5 | John Siebels | 60 | Head | Farmer | Germany |
| 6 | Meta Siebels | 54 | Wife | — | Germany |
| 7 | Jacob Siebels | 23 | Son | Farmer Laborer | Iowa |
| 8 | Leona Siebels | 17 | Daughter | Music Teacher | Iowa |
| 9 | William Richards | 56 | Head | Farmer | Wisconsin |
| 10 | Lottie Richards | 52 | Sister | — | Wisconsin |
| 11 | Vern Woldt | 40 | Hired hand | Farm Laborer | S. Dak. |
| 12 | Grace Becker | 22 | Servant | Housekeeper | S. Dak. |
| 13 | Leo Kirstein | 43 | Head | Farmer | S. Dak. |
| 14 | Ruby Kirstein | 33 | Wife | — | S. Dak. |
| 15 | Leo Junior Kirstein | 8 | Son | — | S. Dak. |
| 16 | Earl Swerts | 22 | Hired hand | Farm Laborer | Montana |
| 17 | M. E. Packard | 56 | Head | Farmer | S. Dak. |
| 18 | May Packard | 55 | Wife | — | New York |
| 19 | Soren Jensen | 50 | Head | Farmer | Denmark |
| 20 | Esther Jensen | 46 | Wife | — | S. Dak. |
| 21 | Vernon Jensen | 22 | Son | Farm Laborer | S. Dak. |
| 22 | Verla Jensen | 19 | Daughter | Teacher | S. Dak. |
| 23 | Raymond Jensen | 17 | Son | Farm Laborer | S. Dak. |
| 24 | Verna Jensen | 15 | Daughter | — | S. Dak. |
| 25 | Arnold Jensen | 13 | Son | — | S. Dak. |
| 26 | Bernice Jensen | 11 | Daughter | — | S. Dak. |
| 27 | Belva Jensen | 9 | Daughter | — | S. Dak. |
| 28 | Janelle Jensen | 6 | Daughter | — | S. Dak. |
| 29 | A. P. Larsen | 60 | Head | Farmer | Denmark |
| 30 | Mary Larsen THIS PERSON | 52 | Wife | Farm Laborer | Iowa |
| 31 | Alvin Larsen | 26 | Son | Farm Laborer | Iowa |
| 32 | Edna Larsen | 20 | Daughter | — | S. Dak. |
| 33 | Elmer Larsen | 18 | Son | Farm Laborer | S. Dak. |
| 34 | Thelma Larsen | 16 | Daughter | — | S. Dak. |
| 35 | Carl Larsen | 14 | Son | — | S. Dak. |
| 36 | Eugene Larsen | 12 | Son | — | S. Dak. |
| 37 | Phyllis Jean Larsen | 12 | Daughter | — | S. Dak. |
| 38 | Clarence P. Haugland | 49 | Head | Farmer | S. Dak. |
| 39 | Hannah Haugland | 51 | Wife | — | Norway |
| 40 | Norman Haugland | 21 | Son | Farm Laborer | S. Dak. |
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)