James Mahoney — 1940 US Census Record

Model Tree available

1940 United States Federal Census · Cook-County, Illinois

Our Model Tree links this James Mahoney across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed), with identified parents John — first a head (b.~1909), then head of a 3-person household.

Age 31 b. ~1909 Male Head Born: Illinois Married

1940 Census Record Details

Census Year	1940
Location	Cook-County, Illinois
Surname	Mahoney
Given Name	James E
Relationship to Head	Head
Sex	M
Color / Race	White
Age	31
Marital Status	Married
Birthplace	Illinois
1935 Residence (City)	Chicago City
1935 Residence (County)	Cook
Additional Details
Occupation	Policeman
Industry	City
Class of Worker	GW
Hours Worked	48
Income (1939)	2400
Highest Grade	H 4
1935 Residence	Same Place
Birth State	Illinois
Birth Country	United States
Birthplace (normalized)	illinois
Occupation	Policeman
Township / Ward	Chicago City
Est. Birth Year	~1909

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 James	Age	Birth yr
James Mahoney	Head	—	31	~1909
Helen Mahoney	Spouse	—	30	~1910
Helen Mahoney	Daughter	—		~1940

Census Appearances

1920

Cook, Illinois

Son, age 11

Cook, Illinois · implied b. ~1909 — 4 household members

● Primary link · ~Confirmed · 2 sources

XGBoost Household

Surname	Mahoney
Given Name	James
Relationship to Head	Son
Sex	M
Color / Race	White
Age	11
Marital Status	Single
Birthplace	Illinois
Father's Birthplace	Illinois
Mother's Birthplace	Illinois
Can Read	Yes
Can Write	Yes
Speaks English	Yes
Birth State	Illinois
Birth Country	United States
Birthplace (normalized)	illinois

1930

Cook, Illinois

Son, age 21

Cook, Illinois · implied b. ~1909 — 7 household members

● Primary link · ~Confirmed · 2 sources

XGBoost Household

Surname	Mahoney
Given Name	James M
Relationship to Head	Son
Sex	M
Color / Race	White
Age	21
Marital Status	Single
Birthplace	Illinois
Father's Birthplace	Illinois
Mother's Birthplace	Illinois
Can Read/Write	Yes
Birth State	Illinois
Birth Country	United States
Birthplace (normalized)	illinois

1940

Cook-County, Illinois

Head, age 31

Cook-County, Illinois · implied b. ~1909 — 3 household members

Surname	Mahoney
Given Name	James E
Relationship to Head	Head
Sex	M
Color / Race	White
Age	31
Marital Status	Married
Birthplace	Illinois
1935 Residence (City)	Chicago City
1935 Residence (County)	Cook
Occupation	Policeman
Industry	City
Class of Worker	GW
Hours Worked	48
Income (1939)	2400
Highest Grade	H 4
1935 Residence	Same Place
Birth State	Illinois
Birth Country	United States
Birthplace (normalized)	illinois

Model Tree

Model Tree available

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

Show:

Gen 1 Parents confidence ≈ 0.92

Father

John Mahoney

b. ~1884

Source father

● Household · direct · ~0.92

This person

Anchor record

James Mahoney

Head · 1940 · age 31 · b. ~1909 · 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-t0627-00958-00394)

Line	Name	Age	Relation	Occupation	Birthplace
1	William Chap	37	Son	—	Illinois
2	George Le Mesurier	45	Son-in-law	Boiler Superintendent	Illinois
3	Louise Le Mesurier	40	Daughter	—	Illinois
4	John Steinbauer	60	Brother-in-law	—	Illinois
5	George P Taylor	58	Head	Foreman	Illinois
6	Sadie Taylor	57	Wife	—	Illinois
7	Connie Rodriguez	17	Lodger	—	Illinois
8	Herbert Storey	32	Head	Electrician	Illinois
9	Lillian Storey	31	Wife	—	Illinois
10	Jane Storey	3	Daughter	—	Illinois
11	Harold Petersen	27	Brother-in-law	Millwright	Illinois
12	Mark Bruce	50	Head	Salesman	Minnesota
13	Agnes Bruce	30	Wife	—	Illinois
14	Gale Bruce	7	Daughter	—	Illinois
15	Fred Kross	41	Head	Salesman	Illinois
16	Lillian Kross	39	Wife	—	Illinois
17	Roy Kross	17	Son	—	Illinois
18	Joan Kross	9	Daughter	—	Illinois
19	James E Mahoney THIS PERSON	31	Head	Policeman	Illinois
20	Helen M Mahoney	30	Wife	—	Illinois
21	Helen Gale Mahoney	0	Daughter	—	Illinois
22	Otto Henneman	47	Head	Auditor	Illinois
23	Jewel Henneman	45	Wife	—	Illinois
24	Mary Ellen Newman	25	Step Daughter	Stenographer	Illinois
25	Jean Keller	23	Step Daughter	Stenographer	Illinois
26	John Thomas Egan	32	Head	Metallurgist	Iowa
27	Genevieve Egan	28	Wife	—	Nebraska
28	Gregory John Egan	1	Son	—	Illinois
29	Patrick C O'Connor	27	Head	Office Worker	Illinois
30	Edith M O'Connor	25	Wife	—	Illinois
31	George Zisterman	45	Head	Repairman	Illinois
32	Madeline Zisterman	40	Wife	—	Illinois
33	Robert Zisterman	8	Son	—	Illinois
34	Shirley Zisterman	14	Daughter	—	Illinois
35	Le Roy Seyffert	27	Head	Pharmacist	Illinois
36	Bernice Seyffert	26	Wife	—	Illinois
37	Anita Seyffert	1	Daughter	—	Illinois
38	William Benton	42	Head	Policeman	Illinois
39	Myrtle Benton	35	Wife	—	Illinois
40	Patricia Benton	6	Daughter	—	Illinois

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Pedigree Summary

James

Gen 1 · 1 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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