ML
Mary Lambert — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cerro-Gordo-County, Iowa
Our Model Tree links this Mary Lambert across the 1930 and 1940 US Censuses in Cerro-Gordo-County, Iowa (XGBoost, ~Confirmed) — first a daughter (b.~1928), then head of a 10-person household.
Age 12
b. ~1928
Female
Daughter
Born: Iowa
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cerro-Gordo-County, Iowa |
| Surname | Lambert |
| Given Name | Mary J |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Mason City |
| 1935 Residence (County) | Cerro Gordo |
| Additional Details | |
| Highest Grade | G 6 |
| 1935 Residence | Same place |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Township / Ward | Mason City |
| Est. Birth Year | ~1928 |
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.
10 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Maxine Lambert | Daughter | — | 18 | ~1922 |
| Mary Lambert | Daughter | — | 12 | ~1928 |
| Jean Lambert | Daughter | — | 14 | ~1926 |
| Patricia Lambert | Daughter | — | 8 | ~1932 |
| Carl Lambert | Head | — | 48 | ~1892 |
| Mary Lambert | Other | — | 80 | ~1860 |
| Roger Lambert | Son | — | 10 | ~1930 |
| Rolland Lambert | Son | — | 10 | ~1930 |
| John Lambert | Son | — | 4 | ~1936 |
| Gertrude Lambert | Spouse | — | 45 | ~1895 |
Census Appearances
1930
Cerro Gordo, …
Daughter, age 2
Cerro Gordo, Iowa · implied b. ~1928 — 8 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Lambert |
| Given Name | Mary Jane |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 2 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Occupation | none |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Cerro-Gordo-County, Iowa
Daughter, age 12
Cerro-Gordo-County, Iowa · implied b. ~1928 — 10 household members
| Surname | Lambert |
| Given Name | Mary J |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 12 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Mason City |
| 1935 Residence (County) | Cerro Gordo |
| Highest Grade | G 6 |
| 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 Lambert across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Lambert
Daughter · 1940 · age 12 · b. ~1928 · Iowa
★ You are viewing this record
Sibling
Roger Lambert
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Patricia Lambert
Sibling · 1940 · age 8
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Jean Lambert
Sibling · 1940 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Maxine Lambert
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Rolland Lambert
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Lambert
Sibling · 1940 · age 4
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
1940 US Federal Census — Cerro-Gordo-County, Iowa
Open full size
1940 US Federal Census — Cerro-Gordo-County, Iowa
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01146-00882)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Louis Thiederman | 8 | Son | — | Iowa |
| 2 | Connie Thiederman | 7 | Daughter | — | Iowa |
| 3 | Gwendolyn Thiederman | 4 | Daughter | — | Iowa |
| 4 | Ben Frank | 21 | Head | Office Clerk | Iowa |
| 5 | Carroll O Frank | 21 | Wife | — | Iowa |
| 6 | David Frank | 1 | Son | — | Iowa |
| 7 | Carl R Lambert | 48 | Head | Railroad Brakeman | Iowa |
| 8 | Gertrude Lambert | 45 | Wife | — | Iowa |
| 9 | Maxine Lambert | 18 | Daughter | Cashier | Iowa |
| 10 | Jean Lambert | 14 | Daughter | — | Iowa |
| 11 | Mary J Lambert THIS PERSON | 12 | Daughter | — | Iowa |
| 12 | Roger Lambert | 10 | Son | — | Iowa |
| 13 | Rolland Lambert | 10 | Son | — | Iowa |
| 14 | Patricia Lambert | 8 | Daughter | — | Iowa |
| 15 | John Lambert | 4 | Son | — | Iowa |
| 16 | Mary Lambert | 80 | Mother | — | Wisconsin |
| 17 | Albert L Schmidt | 42 | Head | Traveling Salesman | Iowa |
| 18 | Alta Schmidt | 41 | Wife | — | Iowa |
| 19 | Dorothy Schmidt | 17 | Daughter | — | Iowa |
| 20 | Marjorie Schmidt | 15 | Daughter | — | Iowa |
| 21 | Dale Schmidt | 14 | Daughter | — | Iowa |
| 22 | Martin D Churchill | 76 | Head | — | Iowa |
| 23 | Elizabeth Churchill | 74 | Wife | — | Illinois |
| 24 | Joseph H Dunsmore | 60 | Head | Flagman | Kansas |
| 25 | Jessie Dunsmore | 57 | Wife | — | Kansas |
| 26 | James Dunsmore | 39 | Son | Fireman | Kansas |
| 27 | Katherine Dunsmore | 35 | Daughter-in-law | Laborer | Germany |
| 28 | Robert Dunsmore | 12 | Grandson | Laborer | Iowa |
| 29 | Marvett Dunsmore | 11 | Grandson | — | Illinois |
| 30 | Vern O Lober | 38 | Head | Train Dispatcher | Iowa |
| 31 | Thelma Lober | 36 | Wife | — | Iowa |
| 32 | Richard Lober | 15 | Son | — | Iowa |
| 33 | Robert Lober | 14 | Son | — | Iowa |
| 34 | Clarence Wagner | 34 | Head | Truck Driver | Iowa |
| 35 | Gertrude Wagner | 33 | Wife | — | Illinois |
| 36 | Gloria C Wagner | 6 | Daughter | — | Iowa |
| 37 | Theron G Fosser | 32 | Head | Yard Foreman | Wisconsin |
| 38 | Archie Fosser | 21 | Brother | Truck Driver | Wisconsin |
| 39 | John Gundiff | 21 | Head | Laborer | Iowa |
| 40 | Velma Gundiff | 19 | Wife | — | Iowa |
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)