Mary Johns — 1940 US Census Record

Linked across censuses

1940 United States Federal Census · Boulder-County, Colorado

Our Model Tree links this Mary Johns across the 1920, 1930 and 1940 US Censuses in Boulder-County, Colorado (XGBoost, ~Confirmed) — first a spouse (b.~1880), then head of a 3-person household.

Age 60 b. ~1880 Female Spouse Born: Colorado Married

1940 Census Record Details

Census Year	1940
Location	Boulder-County, Colorado
Surname	Johns
Given Name	Mary D.
Relationship to Head	wife
Sex	F
Color / Race	White
Age	60
Marital Status	Married
Birthplace	Colorado
1935 Residence (City)	Lafayette
1935 Residence (County)	Boulder
Additional Details
Hours Worked	0
Highest Grade	No 8
1935 Residence	Same place
Birth State	Colorado
Birth Country	United States
Birthplace (normalized)	colorado
Township / Ward	Lafayette
Est. Birth Year	~1880

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
Carrie Johns	Daughter	—	21	~1919
Mary Johns	Spouse	—	60	~1880
Edwin Johns	Head	—	64	~1876

Census Appearances

1920

Boulder, Colorado

Spouse, age 40

Boulder, Colorado · implied b. ~1880 — 4 household members

● Primary link · ~Confirmed · 2 sources

XGBoost Household

Surname	John
Given Name	Mary
Relationship to Head	Wife
Sex	F
Color / Race	White
Age	40
Marital Status	Married
Birthplace	Colorado
Father's Birthplace	Illinois
Mother's Birthplace	Illinois
Can Read	Yes
Can Write	Yes
Speaks English	Yes
Birth State	Colorado
Birth Country	United States
Birthplace (normalized)	colorado

1930

Boulder, Colorado

Other, age 50

Boulder, Colorado · implied b. ~1880 — 3 household members

● Primary link · ~Confirmed · 2 sources

XGBoost Household

Surname	John
Given Name	Mary
Relationship to Head	Wife H
Sex	F
Color / Race	White
Age	50
Marital Status	Married
Birthplace	Colorado
Age at First Marriage	20
Father's Birthplace	Illinois
Mother's Birthplace	Illinois
Can Read/Write	Yes
Birth State	Colorado
Birth Country	United States
Birthplace (normalized)	colorado

1940

Boulder-County, Colorado

Spouse, age 60

Boulder-County, Colorado · implied b. ~1880 — 3 household members

Surname	Johns
Given Name	Mary D.
Relationship to Head	wife
Sex	F
Color / Race	White
Age	60
Marital Status	Married
Birthplace	Colorado
1935 Residence (City)	Lafayette
1935 Residence (County)	Boulder
Hours Worked	0
Highest Grade	No 8
1935 Residence	Same place
Birth State	Colorado
Birth Country	United States
Birthplace (normalized)	colorado

Model Tree

Linked across censuses

Our Model Tree links Mary Johns 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 Johns

Spouse · 1940 · age 60 · b. ~1880 · Colorado

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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 — Boulder-County, Colorado Open full size

Page Contents

40 people indexed on this census page (nara:1940:m-t0627-00457-00161)

Line	Name	Age	Relation	Occupation	Birthplace
1	Roman Cernich	56	head	Miner	Jugo Slavia
2	Josephine Cernich	51	wife	—	Jugo Slavia
3	Anna Cernich	26	daughter	—	Iowa
4	John Cernich	22	son	Floor Sander	Iowa
5	Frank Cernich	19	son	—	Iowa
6	Catherine Cernich	17	daughter	—	Iowa
7	Dorothy Cernich	15	daughter	—	Iowa
8	Agnes L. Cernich	12	daughter	—	Wyoming
9	William Snow	64	head	—	Massachusetts
10	Cyril Snow	32	son	Miner	Colorado
11	Joseph Sheader	43	head	Miner	England
12	Viola Sheader	37	wife	—	Colorado
13	Harold Sheader	18	son	Laborer	Colorado
14	Loraine Sheader	18	daughter	—	Arkansas
15	William Betton	20	nephew	Farm Worker	Colorado
16	Viola Betton	18	niece	Errand Girl	Colorado
17	Eva Betton	15	niece	—	Colorado
18	William Hanson	76	father in law	—	Pennsylvania
19	Lafayette Schofield	35	head	Trucker	Colorado
20	Josephine Schofield	31	wife	—	Oklahoma
21	Phyllis Schofield	11	daughter	—	Colorado
22	Billie Schofield	5	son	—	Colorado
23	William Schofield	70	head	—	Massachusetts
24	Rena J. Schofield	57	wife	—	Colorado
25	Glen Schofield	33	head	Trucker	Colorado
26	Edna Schofield	33	wife	—	Iowa
27	Glenn Lee Schofield	11	son	—	Colorado
28	Kenneth Schofield	11	son	—	Colorado
29	Clifford Schofield	10	son	—	Colorado
30	Ernest Anderson	58	head	Miner	Sweden
31	Marie Anderson	21	daughter	Receptionist	Colorado
32	Helen Anderson	14	daughter	—	Colorado
33	Elois Anderson	11	daughter	—	Colorado
34	Lee Baker	50	head	Manager	Colorado
35	Irma Baker	44	wife	—	Colorado
36	Edwin Johns	64	head	Mine Foreman	Ohio
37	Mary D. Johns THIS PERSON	60	wife	—	Colorado
38	Carrie (Ab) Johns	21	daughter	—	Colorado
39	George Stevens	46	head	Coal Miner	Pennsylvania
40	Alma E. Stevens	50	wife	—	Iowa

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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)

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