John Larsen — 1940 US Census Record

Model Tree available

1940 United States Federal Census · Cook-County, Illinois

Our Model Tree links this John Larsen across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed), with identified parents Jacob & Alexandra — first a head (b.~1917), then head of a 3-person household.

Age 23 b. ~1917 Male Head Born: Illinois Married

1940 Census Record Details

Census Year	1940
Location	Cook-County, Illinois
Surname	Larsen
Given Name	John
Relationship to Head	Head
Sex	M
Color / Race	White
Age	23
Marital Status	Married
Birthplace	Illinois
1935 Residence (City)	Chicago
1935 Residence (County)	Cook
Additional Details
Occupation	Printer
Industry	Printing Co
Class of Worker	PW
Hours Worked	42
Income (1939)	310
Highest Grade	H-2
1935 Residence	Same place
Birth State	Illinois
Birth Country	United States
Birthplace (normalized)	illinois
Occupation	Printer
Township / Ward	Chicago
Est. Birth Year	~1917

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 John	Age	Birth yr
Thomas Larsen	Son	—		~1940
Mary Larsen	Spouse	—	23	~1917
John Larsen	Head	—	23	~1917

Census Appearances

1920

Cook, Illinois

Son, age 2

Cook, Illinois · implied b. ~1918 — 10 household members

● Primary link · ~Confirmed · 2 sources

XGBoost Household

Surname	Larsen
Given Name	John
Relationship to Head	Son
Sex	M
Color / Race	White
Age	2
Marital Status	Single
Birthplace	Illinois
Father's Birthplace	Norway
Mother's Birthplace	Sweden
Mother Tongue	Swedish
Birth State	Illinois
Birth Country	United States
Birthplace (normalized)	illinois

1930

Cook, Illinois

Son, age 12

Cook, Illinois · implied b. ~1918 — 8 household members

● Primary link · ~Confirmed · 2 sources

XGBoost Household

Surname	Larsen
Given Name	John H.
Relationship to Head	Son
Sex	M
Color / Race	White
Age	12
Marital Status	Single
Birthplace	Illinois
Father's Birthplace	Norway
Mother's Birthplace	Sweden
Occupation	none
Can Read/Write	Yes
Birth State	Illinois
Birth Country	United States
Birthplace (normalized)	illinois

1940

Cook-County, Illinois

Head, age 23

Cook-County, Illinois · implied b. ~1917 — 3 household members

Surname	Larsen
Given Name	John
Relationship to Head	Head
Sex	M
Color / Race	White
Age	23
Marital Status	Married
Birthplace	Illinois
1935 Residence (City)	Chicago
1935 Residence (County)	Cook
Occupation	Printer
Industry	Printing Co
Class of Worker	PW
Hours Worked	42
Income (1939)	310
Highest Grade	H-2
1935 Residence	Same place
Birth State	Illinois
Birth Country	United States
Birthplace (normalized)	illinois

Model Tree

Model Tree available

Our Model Tree links John Larsen across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Jacob Larsen (~0.92 confidence) and mother Alexandra Larsen (~0.92 confidence). The pedigree spans 1 generation with 2 identified ancestors.

Show:

Gen 1 Parents confidence ≈ 0.92

Father

Jacob Larsen

b. ~1874

Source father

● Household · direct · ~0.92

Mother

Alexandra Larsen

b. ~1882

Source mother

● Household · direct · ~0.92

This person

Anchor record

John Larsen

Head · 1940 · age 23 · b. ~1917 · 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 — Cook-County, Illinois Open full size

Page Contents

40 people indexed on this census page (nara:1940:m-t0627-00979-00399)

Line	Name	Age	Relation	Occupation	Birthplace
1	Max Fosdick	51	Head	Shoe Salesman	Russia
2	Kate Fosdick	46	Wife	—	Russia
3	Mollie Fosdick	21	Daughter	Saleslady	Illinois
4	Lillian Fosdick	14	Daughter	—	Illinois
5	Sharon Fosdick	4	Son	—	Illinois
6	John Kirby	47	Head	Principal Clerk	Illinois
7	Ida Kirby	34	Wife	—	Russia
8	Burton Kirby	13	Son	—	Illinois
9	Julian Kirby	10	Son	—	Illinois
10	Edward Kirby	2	Son	—	Illinois
11	Joseph Mullen	50	Head	Bailiff	Illinois
12	Alice Mullen	36	Wife	—	Michigan
13	Kenneth Mullen	1	Son	—	Michigan
14	Thomas Brant	70	Head	—	W. Virginia
15	William Brant	40	Son	Salesman	Illinois
16	John Larsen THIS PERSON	23	Head	Printer	Illinois
17	Mary Larsen	23	Wife	—	Illinois
18	Thomas Larsen	0	Son	—	Illinois
19	Christ Valis	46	Head	Manager	Greece
20	Bessie Valis	41	Wife	—	Greece
21	Annie Valis	16	Daughter	—	Illinois
22	Esther Valis	14	Daughter	—	Illinois
23	Frances Valis	7	Daughter	—	Illinois
24	Bernard Hogan	36	Head	Building Appraiser	Illinois
25	Mary Hogan	33	Wife	—	Illinois
26	Marianne Hogan	1	Daughter	—	Illinois
27	Agnes Mclaughlin	58	Mother-in-law	—	Illinois
28	Thomas Mclaughlin	35	Brother-in-law	Police Sergeant	Illinois
29	Clara M. Wilson	69	Head	—	Iowa
30	Margaret E. Moore	59	Sister-in-law	Housekeeper	Missouri
31	Charles Le Veir	48	Head	Linotype Operator	Maryland
32	Rose Le Veir	44	Wife	—	Illinois
33	Charles Le Veir	21	Son	Usher	Illinois
34	Charles Jr. Le Veir	15	Son	—	Illinois
35	John Fender	61	Head	Salesman	Illinois
36	Josephine Fender	63	Wife	—	Illinois
37	Hester Goss	45	Sister-in-law	Telephone Operator	Illinois
38	John E. Gill	56	Head	Clerk	Iowa
39	Cora E. Gill	58	Wife	—	New York
40	Wilkin A. Gill	54	Brother	Lawyer	Iowa

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Pedigree Summary

John

Gen 1 · 2 parents ~0.92

Max depth 4 (1900–1950 window)

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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