WM
William Mcmahon — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Delaware-County, Iowa
Our Model Tree links this William Mcmahon across the 1930 and 1940 US Censuses in Delaware-County, Iowa (XGBoost, ~Confirmed) — first a head (b.~1885), then head of a 7-person household.
Age 55
b. ~1885
Male
Head
Born: Iowa
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Delaware-County, Iowa |
| Surname | McMahon |
| Given Name | William |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 55 |
| Marital Status | Married |
| Birthplace | Iowa |
| 1935 Residence (City) | Prairie Twp |
| 1935 Residence (County) | Delaware |
| Additional Details | |
| Occupation | Farmer |
| Industry | Farm |
| Class of Worker | OA |
| Hours Worked | 48 |
| Income (1939) | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same House |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Occupation | Farmer |
| Township / Ward | Prairie Twp |
| Est. Birth Year | ~1885 |
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.
7 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to William | Age | Birth yr |
|---|---|---|---|---|
| Lorraine Mcmahon | Daughter | — | 15 | ~1925 |
| Raymond Mcmahon | Son | — | 5 | ~1935 |
| Harold Mcmahon | Son | — | 12 | ~1928 |
| Mary Mcmahon | Spouse | — | 39 | ~1901 |
| William Mcmahon | Head | — | 55 | ~1885 |
| Virginia Mcmahon | Daughter | — | 9 | ~1931 |
| Donald Mcmahon | Son | — | 1 | ~1939 |
Census Appearances
1930
Delaware, Iowa
Head, age 45
Delaware, Iowa · implied b. ~1885 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | William J. |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 45 |
| Marital Status | Married |
| Birthplace | Iowa |
| Age at First Marriage | 39 |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Connecticut |
| Occupation | Farmer |
| Industry | General Farm |
| Class of Worker | VVV |
| Can Read/Write | Yes |
| Home Owned/Rented | O |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Delaware-County, Iowa
Head, age 55
Delaware-County, Iowa · implied b. ~1885 — 7 household members
| Surname | McMahon |
| Given Name | William |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | White |
| Age | 55 |
| Marital Status | Married |
| Birthplace | Iowa |
| 1935 Residence (City) | Prairie Twp |
| 1935 Residence (County) | Delaware |
| Occupation | Farmer |
| Industry | Farm |
| Class of Worker | OA |
| Hours Worked | 48 |
| Income (1939) | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same House |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
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 William Mcmahon across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
William Mcmahon
Head · 1940 · age 55 · b. ~1885 · Iowa
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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 — Delaware-County, Iowa
Open full size
1940 US Federal Census — Delaware-County, Iowa
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01155-00466)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Catherine Noble | 63 | Wife | Housekeeper | California |
| 2 | May Noble | 41 | Daughter | Beauty Shop Operator | Iowa |
| 3 | Mildred Noble | 39 | Daughter | Housekeeper | Iowa |
| 4 | William Mcmahon THIS PERSON | 55 | Head | Farmer | Iowa |
| 5 | Mary V. Mcmahon | 39 | Wife | Housekeeper | Iowa |
| 6 | Lorraine Mcmahon | 15 | Daughter | — | Iowa |
| 7 | Harold Mcmahon | 12 | Son | — | Iowa |
| 8 | Virginia Mcmahon | 9 | Daughter | — | Iowa |
| 9 | Raymond Mcmahon | 5 | Son | — | Iowa |
| 10 | Donald Mcmahon | 1 | Son | — | Iowa |
| 11 | Robert Kennedy | 46 | Head | Farmer | Iowa |
| 12 | Margaret Kennedy | 38 | Wife | Housekeeper | Iowa |
| 13 | Thomas Kennedy | 50 | Brother | Farmer | Iowa |
| 14 | Bernice Kennedy | 17 | Daughter | — | Iowa |
| 15 | David Kennedy | 16 | Son | Farmer | Iowa |
| 16 | Wesley Kennedy | 14 | Son | Farmer | Iowa |
| 17 | William Kennedy | 11 | Son | — | Iowa |
| 18 | Bernice Kennedy | 3 | Daughter | — | Iowa |
| 19 | Archie Keenan | 38 | Head | Farmer | Iowa |
| 20 | Mary Keenan | 35 | Wife | Housekeeper | Iowa |
| 21 | Daniel Keenan | 75 | Father | — | Eire |
| 22 | Harold Keenan | 11 | Son | — | Iowa |
| 23 | John Keenan | 7 | Son | — | Iowa |
| 24 | Amiel Schymanski | 24 | Hired Hand | Laborer | Iowa |
| 25 | Emel Swanson | 52 | Head | Farmer | Sweden |
| 26 | Blenda Swanson | 50 | Wife | Housekeeper | Sweden |
| 27 | William Flanagan | 73 | Head | Farmer | New York |
| 28 | Francis Flanagan | 22 | Son | Farmer | Iowa |
| 29 | Genevieve Flanagan | 19 | Daughter | Housekeeper | Illinois |
| 30 | Robert Flanagan | 2 | Grandson | — | Iowa |
| 31 | Gerald Flanagan | 1 | Grandson | — | Iowa |
| 32 | Edward Hyness | 61 | Head | Farmer | Wisconsin |
| 33 | Mary Hyness | 63 | Wife | Housekeeper | Wisconsin |
| 34 | Edward Jr. Hyness | 22 | Son | Farmer | Iowa |
| 35 | Clarence Francois | 36 | Head | Farmer | Iowa |
| 36 | Ida Francois | 32 | Wife | Housekeeper | Iowa |
| 37 | Edward Francois | 12 | Son | — | Iowa |
| 38 | Robert Francois | 10 | Son | — | Iowa |
| 39 | Leo Francois | 9 | Son | — | Iowa |
| 40 | Dorothy Francois | 8 | Daughter | — | Iowa |
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)