MC
Mary Campbell — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Clay-County, Illinois
Our Model Tree links this Mary Campbell across the 1920, 1930 and 1940 US Censuses in Clay-County, Illinois (XGBoost, ~Confirmed) — first a head (b.~1856), then head of a 2-person household.
Age 84
b. ~1856
Female
Head
Born: Ohio
Widowed
1940 Census Record Details
| Census Year | 1940 |
| Location | Clay-County, Illinois |
| Surname | Campbell |
| Given Name | Mary |
| Relationship to Head | head |
| Sex | F |
| Color / Race | White |
| Age | 84 |
| Marital Status | Widowed |
| Birthplace | Ohio |
| 1935 Residence (County) | Clay |
| Additional Details | |
| Class of Worker | U |
| Income (1939) | 0 |
| Highest Grade | 5 |
| 1935 Residence | Same place |
| Birth State | Ohio |
| Birth Country | United States |
| Birthplace (normalized) | ohio |
| Township / Ward | Clay City Township |
| Est. Birth Year | ~1856 |
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.
2 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Laura Walls | Daughter | — | 57 | ~1883 |
| Mary Campbell | Head | — | 84 | ~1856 |
Census Appearances
1920
Clay, Illinois
Spouse, age 62
Clay, Illinois · implied b. ~1858 — 2 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Campbell |
| Given Name | Mary E |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 62 |
| Marital Status | Married |
| Birthplace | Ohio |
| Father's Birthplace | Ohio |
| Mother's Birthplace | Ohio |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | Ohio |
| Birth Country | United States |
| Birthplace (normalized) | ohio |
1930
Clay, Illinois
Head, age 72
Clay, Illinois · implied b. ~1858
●
Primary link
· ~Confirmed · 1 source
XGBoost
| Surname | Campbell |
| Given Name | Mary |
| Relationship to Head | Head |
| Sex | F |
| Color / Race | White |
| Age | 72 |
| Marital Status | Widowed |
| Birthplace | Ohio |
| Father's Birthplace | Ohio |
| Mother's Birthplace | Ohio |
| Occupation | Farm Owner |
| Industry | Grain farm |
| Class of Worker | W |
| Can Read/Write | Yes |
| Home Owned/Rented | O |
| Birth State | Ohio |
| Birth Country | United States |
| Birthplace (normalized) | ohio |
1940
Clay-County, Illinois
Head, age 84
Clay-County, Illinois · implied b. ~1856 — 2 household members
| Surname | Campbell |
| Given Name | Mary |
| Relationship to Head | head |
| Sex | F |
| Color / Race | White |
| Age | 84 |
| Marital Status | Widowed |
| Birthplace | Ohio |
| 1935 Residence (County) | Clay |
| Class of Worker | U |
| Income (1939) | 0 |
| Highest Grade | 5 |
| 1935 Residence | Same place |
| Birth State | Ohio |
| Birth Country | United States |
| Birthplace (normalized) | ohio |
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 Campbell across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Campbell
Head · 1940 · age 84 · b. ~1856 · Illinois
★ 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 — Clay-County, Illinois
Open full size
1940 US Federal Census — Clay-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00769-00089)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Jay Magness | 4 | son | — | Illinois |
| 2 | Delmar Mcnair | 29 | head | 40 | Illinois |
| 3 | Veva Mcnair | 31 | wife | — | Illinois |
| 4 | Clyde Mcnair | 6 | son | — | Illinois |
| 5 | Gayle Mcnair | 1 | daughter | — | Illinois |
| 6 | Robert Lynn | 25 | head | 40 | Texas |
| 7 | Irene Lynn | 25 | wife | — | Texas |
| 8 | Dennis L. Lynn | 4 | son | — | Texas |
| 9 | Bobbie Lynn | 2 | son | — | Texas |
| 10 | Lewis Clark | 33 | head | 42 | Illinois |
| 11 | Mary Clark | 32 | wife | — | Illinois |
| 12 | Gary L. Clark | 2 | son | — | Illinois |
| 13 | Joan Robinson | 15 | daughter | — | Illinois |
| 14 | Thomas Clark | 22 | head | 40 | Illinois |
| 15 | Kathryn Clark | 20 | wife | — | Illinois |
| 16 | Henry Seregham | 53 | head | — | Illinois |
| 17 | James Abernathy | 34 | head | 40 | Indiana |
| 18 | Wilmetta Abernathy | 29 | wife | — | Illinois |
| 19 | Sammy Nell Abernathy | 7 | daughter | — | Oklahoma |
| 20 | Martin Roberts | 35 | head | 40 | Illinois |
| 21 | Edna Roberts | 33 | wife | — | Illinois |
| 22 | Lawrence Roberts | 14 | son | — | Illinois |
| 23 | William Smith | 47 | head | 42 | Illinois |
| 24 | Carida Smith | 42 | wife | — | Illinois |
| 25 | Harold Smith | 21 | son | 40 | Illinois |
| 26 | Sarah Smith | 17 | daughter | — | Illinois |
| 27 | Robert Smith | 14 | son | — | Illinois |
| 28 | June Smith | 12 | daughter | — | Illinois |
| 29 | Donald Smith | 11 | son | — | Illinois |
| 30 | Jennie Smith | 4 | daughter | — | Illinois |
| 31 | Tomas Tetrick | 78 | head | 40 | Illinois |
| 32 | Sallie Tetrick | 70 | wife | — | Illinois |
| 33 | Mary Campbell THIS PERSON | 84 | head | — | Ohio |
| 34 | Laura Walls | 57 | daughter | — | Illinois |
| 35 | Arthur Pruitt | 43 | head | 45 | Illinois |
| 36 | Joseph Mccalister | 64 | head | 40 | Illinois |
| 37 | Mildred Mccalister | 60 | wife | — | Illinois |
| 38 | Lydea Arnold | 77 | aunt | — | Indiana |
| 39 | Dupree Ingram | 33 | head | 40 | Texas |
| 40 | Edna Ingram | 33 | wife | — | Kansas |
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)