TM
Thomas Mcmahon — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Thomas Mcmahon across the 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a son (b.~1913), then head of a 11-person household.
Age 27
b. ~1913
Male
Son
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | McMahon |
| Given Name | Thomas E. |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | River Forest Village |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Occupation | general clerk |
| Industry | grain brokerage |
| Class of Worker | PW |
| Hours Worked | 12 |
| Income (1939) | 180 |
| Highest Grade | C-1 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Occupation | General Clerk |
| Township / Ward | River Forest Village |
| Est. Birth Year | ~1913 |
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.
11 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Thomas | Age | Birth yr |
|---|---|---|---|---|
| Raymond Mcmahon | Son | — | 13 | ~1927 |
| John Mcmahon | Son | — | 23 | ~1917 |
| William Mcmahon | Son | — | 4 | ~1936 |
| Mary Mcmahon | Daughter | — | 20 | ~1920 |
| James Mcmahon | Son | — | 10 | ~1930 |
| Joseph Mcmahon | Head | — | 55 | ~1885 |
| Joseph Mcmahon | Son | — | 25 | ~1915 |
| Thomas Mcmahon | Son | — | 27 | ~1913 |
| Mary Mcmahon | Spouse | — | 52 | ~1888 |
| George Mcmahon | Son | — | 16 | ~1924 |
| Jeanne Mcmahon | Daughter | — | 12 | ~1928 |
Census Appearances
1930
Cook, Illinois
Son, age 18
Cook, Illinois · implied b. ~1912 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Thomas |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 18 |
| 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
Son, age 27
Cook-County, Illinois · implied b. ~1913 — 11 household members
| Surname | McMahon |
| Given Name | Thomas E. |
| Relationship to Head | son |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | River Forest Village |
| 1935 Residence (County) | Cook |
| Occupation | general clerk |
| Industry | grain brokerage |
| Class of Worker | PW |
| Hours Worked | 12 |
| Income (1939) | 180 |
| Highest Grade | C-1 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
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 Thomas Mcmahon across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Thomas Mcmahon
Son · 1940 · age 27 · b. ~1913 · Illinois
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Sibling
William Mcmahon
Sibling · 1940 · age 4
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Mcmahon
Sibling · 1940 · age 25
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Mary Mcmahon
Sibling · 1940 · age 20
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Jeanne Mcmahon
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
James Mcmahon
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Mcmahon
Sibling · 1940 · age 23
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
George Mcmahon
Sibling · 1940 · age 16
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Raymond Mcmahon
Sibling · 1940 · age 13
Source co-child of head (derived)
● Co-child · derived · ~0.88
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
1940 US Federal Census — Cook-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00788-00522)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Florence D. Mcclercy | 47 | wife | — | Illinois |
| 2 | Florence A. Mcclercy | 22 | daughter | — | Illinois |
| 3 | Norman J. Jr. Mcclercy | 14 | son | — | Indiana |
| 4 | Mary Rose Mcclercy | 18 | daughter | — | Illinois |
| 5 | Joseph A. Mcmahon | 55 | head | Proprietor | Illinois |
| 6 | Mary K. Mcmahon | 52 | wife | — | Illinois |
| 7 | Joseph A. Jr. Mcmahon | 25 | son | Undertaker'S Assistant | Illinois |
| 8 | John F. Mcmahon | 23 | son | Circulator | Illinois |
| 9 | Thomas E. Mcmahon THIS PERSON | 27 | son | General Clerk | Illinois |
| 10 | Mary Beth Mcmahon | 20 | daughter | — | Illinois |
| 11 | George W. Mcmahon | 16 | son | — | Illinois |
| 12 | Raymond Mcmahon | 13 | son | — | Illinois |
| 13 | Jeanne Mcmahon | 12 | daughter | — | Illinois |
| 14 | James Mcmahon | 10 | son | — | Illinois |
| 15 | William Mcmahon | 4 | son | — | Illinois |
| 16 | Edwin R. Carter | 61 | head | Actuary | Iowa |
| 17 | Grace A. Carter | 57 | wife | — | Iowa |
| 18 | Edwin R. Jr. Carter | 31 | son | Radio Operator | Illinois |
| 19 | Fred A. Radtke | 48 | head | Accountant | Ohio |
| 20 | Adelheid Radtke | 47 | wife | — | Illinois |
| 21 | Schrade Radtke | 20 | son | — | Minnesota |
| 22 | George Schrade | 76 | father-in-law | — | Germany |
| 23 | William Cargueroth | 76 | head | — | Illinois |
| 24 | Lillie T. Cargueroth | 67 | wife | — | Illinois |
| 25 | Frank S. Cargueroth | 43 | son | Sales Clerk | Illinois |
| 26 | Clara M. Cargueroth | 47 | daughter-in-law | Saleswoman | Illinois |
| 27 | Frank S. Jr. Cargueroth | 20 | grandson | — | Illinois |
| 28 | Jeanne Cargueroth | 16 | granddaughter | — | Illinois |
| 29 | Matilda Homer | 61 | head | Teacher-Piano | Pennsylvania |
| 30 | Marion Homer | 53 | sister | Teacher | Pennsylvania |
| 31 | Philip G. Campbell | 65 | head | Division Superintendent | Wisconsin |
| 32 | Eva M. Campbell | 57 | wife | — | Iowa |
| 33 | Raymond L. Mcvean | 52 | head | Attorney | Ohio |
| 34 | Belle M. Mcvean | 50 | wife | — | Illinois |
| 35 | Rose Mary Mcvean | 18 | daughter | — | Illinois |
| 36 | Cecelia Mcvean | 13 | daughter | — | Illinois |
| 37 | Wm Henry Van Riper | 38 | head | Advertising Manager | New York |
| 38 | Veronica Van Riper | 36 | wife | — | Missouri |
| 39 | Wilbur Van Riper | 10 | son | — | Illinois |
| 40 | Richard Van Riper | 8 | son | — | Illinois |
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)