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Margaret Mcmahon — 1940 US Census Record
Model Tree available1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Margaret Mcmahon across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed), with identified parents Fred & Fred — first a spouse (b.~1910), then head of a 3-person household.
Age 30
b. ~1910
Female
Spouse
Born: Illinois
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | McMahon |
| Given Name | Margaret |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 30 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Additional Details | |
| Highest Grade | C 3 |
| 1935 Residence | Same place |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1910 |
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 Margaret | Age | Birth yr |
|---|---|---|---|---|
| John Mcmahon | Head | — | 30 | ~1910 |
| Margaret Mcmahon | Spouse | — | 30 | ~1910 |
| John Mcmahon | Son | — | 2 | ~1938 |
Census Appearances
1920
Cook, Illinois
Daughter, age 9
Cook, Illinois · implied b. ~1911 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Margaret |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 9 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Illinois |
| Mother's Birthplace | Illinois |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | German |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1930
Cook, Illinois
Daughter, age 19
Cook, Illinois · implied b. ~1911 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Margaret |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 19 |
| 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
Spouse, age 30
Cook-County, Illinois · implied b. ~1910 — 3 household members
| Surname | McMahon |
| Given Name | Margaret |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 30 |
| Marital Status | Married |
| Birthplace | Illinois |
| 1935 Residence (City) | Chicago City |
| 1935 Residence (County) | Cook |
| Highest Grade | C 3 |
| 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 Margaret Mcmahon across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Fred Mcmahon (~0.92 confidence) and father Fred Mcmahon (~0.92 confidence) and mother Katherine Mcmahon (~0.92 confidence). The pedigree spans 1 generation with 3 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Fred Mcmahon
b. ~1880
Source father
● Household
· direct · ~0.92
Father
Fred Mcmahon
b. ~1875
Source father
● Household
· direct · ~0.92
Mother
Katherine Mcmahon
b. ~1888
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Margaret Mcmahon
Spouse · 1940 · age 30 · b. ~1910 · 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
1940 US Federal Census — Cook-County, Illinois
Page Contents
38 people indexed on this census page (nara:1940:m-t0627-00954-00837)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Robert Worsham | 63 | Head | Florist | California |
| 2 | Lillian Worsham | 59 | Wife | — | Wisconsin |
| 3 | Evelyn M. Worsham | 32 | Daughter | Stenographer | Illinois |
| 4 | Robert S. Worsham | 25 | Son | Salesman | Illinois |
| 5 | Jeanette C. Worsham | 16 | Daughter | — | Illinois |
| 6 | James G. Worsham | 14 | Son | — | Illinois |
| 7 | Ellen O. Buckley | 51 | Head | — | Irish Free State |
| 8 | Catherine Buckley | 24 | Daughter | Mail Sorter | Illinois |
| 9 | Gerald Buckley | 21 | Son | Delivery Boy | Illinois |
| 10 | John Buckley | 16 | Son | — | Illinois |
| 11 | Robert Buckley | 11 | Son | — | Illinois |
| 12 | Bernard Buckley | 20 | Son | — | Illinois |
| 13 | John J. Mcmahon | 30 | Head | Teacher | Illinois |
| 14 | Margaret Mcmahon THIS PERSON | 30 | Wife | — | Illinois |
| 15 | John, Jr. Mcmahon | 2 | Son | — | Illinois |
| 16 | Fritchof Grinde | 46 | Head | Foreman | Wisconsin |
| 17 | Dorothy Grinde | 40 | Wife | Statistical Clerk | Illinois |
| 18 | William Barkhoff | 37 | Head | Accountant | Iowa |
| 19 | Adeline Barkhoff | 35 | Wife | — | Illinois |
| 20 | Frank Schabes | 40 | Head | Heating Engineer | Illinois |
| 21 | Herberta Schabes | 39 | Wife | — | Illinois |
| 22 | Marion Schabes | 16 | Daughter | — | Illinois |
| 23 | Dolores Schabes | 12 | Daughter | — | Illinois |
| 24 | Mary Nordas | 72 | Head | — | Wisconsin |
| 25 | George N. Watson | 65 | Head | Elevator Operator | Illinois |
| 26 | Louise J. Watson | 64 | Wife | — | Illinois |
| 27 | James E. Watson | 20 | Grandson | New Worker | Illinois |
| 28 | James Young | 42 | Lodger | Book Keeper | Scotland |
| 29 | Robert Tilling | 33 | Head | Photographer | Illinois |
| 30 | Catherine Tilling | 33 | Wife | — | Illinois |
| 31 | Virginia Tilling | 1 | Daughter | — | Illinois |
| 34 | Alexander Jenka | 32 | Lodger | Conductor | Poland |
| 35 | Theodore Jenka | 29 | Lodger | Factory | Poland |
| 36 | Miles J. Lucey | 70 | Head | Steel Inspector | Ohio |
| 37 | Catherine Lucey | 69 | Wife | — | Wales |
| 38 | Leah Jenkins | 79 | Sister-in-law | — | Wales |
| 39 | William R. Panka | 56 | Head | Freight Car Inspector | Illinois |
| 40 | Minnie Panka | 50 | Wife | — | Illinois |
Pedigree Summary
Margaret
Gen 1 · 3 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)