MD
Mary Decker — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Lake-County, Illinois
Our Model Tree links this Mary Decker across the 1920, 1930 and 1940 US Censuses in Lake-County, Illinois (XGBoost, ~Confirmed) — first a spouse (b.~1877), then head of a 3-person household.
Age 63
b. ~1877
Female
Spouse
Born: Holland
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Lake-County, Illinois |
| Surname | Decker |
| Given Name | Mary |
| Relationship to Head | wife |
| Sex | F |
| Color / Race | White |
| Age | 63 |
| Marital Status | Married |
| Birthplace | Holland |
| 1935 Residence (City) | Waukegan City |
| 1935 Residence (County) | Lake |
| Naturalization Status | Naturalized |
| Additional Details | |
| Class of Worker | 0 |
| Hours Worked | 0 |
| Highest Grade | 6 |
| 1935 Residence | Same house |
| Birth Country | Netherlands |
| Birthplace (normalized) | holland |
| Township / Ward | Waukegan City |
| Est. Birth Year | ~1877 |
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.
3 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Fred Decker | Head | — | 64 | ~1876 |
| Mary Decker | Spouse | — | 63 | ~1877 |
| Arthur Decker | Son | — | 36 | ~1904 |
Census Appearances
1920
Lake, Illinois
Spouse, age 42
Lake, Illinois · implied b. ~1878 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Decker |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 42 |
| Marital Status | Married |
| Birthplace | Holland |
| Year of Immigration | 1878 |
| Naturalization Status | Naturalized |
| Father's Birthplace | Holland |
| Mother's Birthplace | Holland |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | Dutch |
| Birth Country | Netherlands |
| Birthplace (normalized) | holland |
1930
Lake, Illinois
Other, age 53
Lake, Illinois · implied b. ~1877 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Decker |
| Given Name | Mary |
| Relationship to Head | wife-H |
| Sex | F |
| Color / Race | White |
| Age | 53 |
| Marital Status | Married |
| Birthplace | Holland |
| Naturalization Status | Naturalized |
| Year of Immigration | 1892 |
| Age at First Marriage | 23 |
| Father's Birthplace | Holland |
| Mother's Birthplace | Holland |
| Occupation | none |
| Can Read/Write | Yes |
| Mother Tongue | Dutch |
| Birth Country | Netherlands |
| Birthplace (normalized) | holland |
1940
Lake-County, Illinois
Spouse, age 63
Lake-County, Illinois · implied b. ~1877 — 3 household members
| Surname | Decker |
| Given Name | Mary |
| Relationship to Head | wife |
| Sex | F |
| Color / Race | White |
| Age | 63 |
| Marital Status | Married |
| Birthplace | Holland |
| 1935 Residence (City) | Waukegan City |
| 1935 Residence (County) | Lake |
| Naturalization Status | Naturalized |
| Class of Worker | 0 |
| Hours Worked | 0 |
| Highest Grade | 6 |
| 1935 Residence | Same house |
| Birth Country | Netherlands |
| Birthplace (normalized) | holland |
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 Decker across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
Mary Decker
Spouse · 1940 · age 63 · b. ~1877 · Illinois
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Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Lake-County, Illinois
Open full size
1940 US Federal Census — Lake-County, Illinois
Page Contents
36 people indexed on this census page (nara:1940:m-t0627-00830-00754)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Agnes May | 19 | daughter | Waitress | Canada |
| 2 | Mary May | 17 | daughter | — | Illinois |
| 3 | Patricia May | 15 | daughter | — | Illinois |
| 4 | Jane May | 14 | daughter | — | Illinois |
| 5 | Betty May | 11 | daughter | — | Illinois |
| 6 | Edward Jr. May | 9 | son | — | Illinois |
| 7 | Roberta May | 7 | daughter | — | Illinois |
| 8 | Jack May | 6 | son | — | Illinois |
| 9 | Richard May | 4 | son | — | Illinois |
| 10 | Thomas Fagan | 37 | head | Carpenter Helper | Illinois |
| 11 | Loretta Fagan | 37 | wife | — | Illinois |
| 12 | Shirley Fagan | 12 | daughter | — | Illinois |
| 17 | Queenie Shamorian | 55 | head | — | Turkey |
| 18 | Frank Shamorian | 24 | son | Welder Apprentice | Mass |
| 19 | Varnil Shamorian | 23 | daughter | Sales Girl | Mass |
| 20 | Mesilla Shamorian | 3 | grandson | — | Illinois |
| 21 | Peter Hassian | 46 | head | Leather Worker | Russia |
| 22 | Andrew Hassian | 16 | son | — | Mass |
| 23 | William Foster | 37 | head | Punch Press Operator | Illinois |
| 24 | Sybil Foster | 37 | wife | Dress Maker | Tennessee |
| 25 | Phil Foster | 12 | son | — | Tennessee |
| 26 | David Spink | 39 | head | Laborer | Michigan |
| 27 | Clara Spink | 40 | wife | — | Illinois |
| 28 | Marjorie Spink | 14 | daughter | — | Illinois |
| 29 | Joan Spink | 12 | daughter | — | Illinois |
| 30 | James Spink | 3 | son | — | Illinois |
| 31 | Mathilda Olson | 64 | head | — | Denmark |
| 32 | Anton Thielson | 70 | brother | — | Denmark |
| 33 | Virginia Gartley | 22 | granddaughter | Fine Glass Worker | Illinois |
| 34 | Jeanne Rudolph | 18 | lodger | Bindery Work | Illinois |
| 35 | Eva Mullner | 63 | head | — | Austria |
| 36 | Louis Mullner | 28 | son | Kitchen Helper | Illinois |
| 37 | Angela Mullner | 29 | daughter-in-law | Golf Maker | Illinois |
| 38 | Fred Decker | 64 | head | — | Germany |
| 39 | Mary Decker THIS PERSON | 63 | wife | — | Holland |
| 40 | Arthur Decker | 36 | son | Truck Driver | Wisconsin |
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)