TM
Thomas Mcmahon — 1940 US Census Record
Model Tree available1940 United States Federal Census · Scott-County, Iowa
Our Model Tree links this Thomas Mcmahon across the 1920, 1930 and 1940 US Censuses in Scott-County, Iowa (XGBoost, ~Confirmed), with identified parents Thomas & Lydia — first a son (b.~1920), then head of a 6-person household.
Age 20
b. ~1920
Male
Son
Born: Iowa
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Scott-County, Iowa |
| Surname | McMahon |
| Given Name | Thomas W |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 20 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Davenport City |
| 1935 Residence (County) | Scott |
| Additional Details | |
| Occupation | Laborer |
| Industry | Boiler manufacture |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 300 |
| Highest Grade | H-4 |
| 1935 Residence | Same place |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Occupation | Laborer |
| Township / Ward | Davenport City |
| Est. Birth Year | ~1920 |
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.
6 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Thomas | Age | Birth yr |
|---|---|---|---|---|
| Johnny Mcmahon | Son | — | 13 | ~1927 |
| Margaret Mcmahon | Daughter | — | 12 | ~1928 |
| Thomas Mcmahon | Son | — | 20 | ~1920 |
| Emma Mcmahon | Other | — | 21 | ~1919 |
| Lydia Mcmahon | Spouse | — | 38 | ~1902 |
| Thomas Mcmahon | Head | — | 40 | ~1900 |
Census Appearances
1920
Scott, Iowa
Son, age
Scott, Iowa · implied b. ~1920 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Thomas W. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 0 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Wisconsin |
| Mother's Birthplace | Illinois |
| Can Read | No |
| Can Write | No |
| Speaks English | No |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1930
Scott, Iowa
Son, age 10
Scott, Iowa · implied b. ~1920 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Thomas |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 10 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Wisconsin |
| Mother's Birthplace | Illinois |
| Can Read/Write | Yes |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Scott-County, Iowa
Son, age 20
Scott-County, Iowa · implied b. ~1920 — 6 household members
| Surname | McMahon |
| Given Name | Thomas W |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 20 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Davenport City |
| 1935 Residence (County) | Scott |
| Occupation | Laborer |
| Industry | Boiler manufacture |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 300 |
| Highest Grade | H-4 |
| 1935 Residence | Same place |
| 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 Thomas Mcmahon across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Thomas Mcmahon (~0.92 confidence) and mother Lydia Mcmahon (~0.92 confidence). The pedigree spans 1 generation with 2 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Thomas Mcmahon
b. ~1900
Source father
● Household
· direct · ~0.92
Mother
Lydia Mcmahon
b. ~1902
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Thomas Mcmahon
Son · 1940 · age 20 · b. ~1920 · Iowa
★ You are viewing this record
Sibling
Margaret Mcmahon
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Johnny 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 — Scott-County, Iowa
Open full size
1940 US Federal Census — Scott-County, Iowa
Page Contents
38 people indexed on this census page (nara:1940:m-t0627-01202-00440)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Henry C Ross | 37 | Head | Clerk | Illinois |
| 42 | Sarah G Ross | 33 | Wife | Teacher | Illinois |
| 43 | Thomas J Mcmahon | 40 | Head | Moulder | Wisconsin |
| 44 | Lydia M Mcmahon | 38 | Wife | — | Illinois |
| 45 | Johnny E Mcmahon | 13 | Son | — | Iowa |
| 46 | Margaret M Mcmahon | 12 | Daughter | — | Iowa |
| 47 | Thomas W Mcmahon THIS PERSON | 20 | Son | Laborer | Iowa |
| 48 | Emma E Mcmahon | 21 | Daughter-in-law | — | Iowa |
| 49 | Amos L Corner | 49 | Head | Boiler Maker | Iowa |
| 50 | Margaret M Corner | 35 | Wife | — | Iowa |
| 51 | Eleanor M Corner | 18 | Daughter | — | Iowa |
| 52 | Kenneth L Corner | 17 | Son | New Worker | Iowa |
| 53 | Mildred L Corner | 16 | Daughter | — | Iowa |
| 54 | Marie F Corner | 13 | Daughter | — | Iowa |
| 55 | Betty R Corner | 12 | Daughter | — | Iowa |
| 56 | Shirley M Corner | 10 | Daughter | — | Iowa |
| 57 | Helen J Corner | 6 | Daughter | — | Iowa |
| 58 | Jeanette A Corner | 4 | Daughter | — | Iowa |
| 59 | Delores O Corner | 1 | Daughter | — | Iowa |
| 60 | Goldie M Stanger | 32 | Head | — | Iowa |
| 61 | William Jr Stanger | 14 | Son | — | Iowa |
| 62 | Eugene A Stanger | 4 | Son | — | Iowa |
| 64 | Rudolph Von Ahnen | 40 | Head | Foreman | Germany |
| 65 | Gertrude A Von Ahnen | 39 | Wife | — | Germany |
| 66 | Margaret G Von Ahnen | 18 | Daughter | New Worker | Iowa |
| 67 | Rudolph L Von Ahnen | 17 | Son | New Worker | Iowa |
| 68 | Henry F Stichler | 50 | Head | Broom Tier | Iowa |
| 69 | Hulda H Stichler | 49 | Wife | — | Iowa |
| 70 | Wade H Stichler | 21 | Son | Attendant | Iowa |
| 71 | Ralph H Hildebrand | 30 | Son-in-law | Operator | Iowa |
| 72 | Melva M Hildebrand | 29 | Daughter | — | Iowa |
| 73 | Gwen J Hildebrand | 7 | Granddaughter | — | Iowa |
| 74 | Darrell E Goedeke | 29 | Head | Foreman | Iowa |
| 75 | Marjorie M Goedeke | 25 | Wife | — | Iowa |
| 77 | James L La Grange | 28 | Head | Moulder | Iowa |
| 78 | Jeanette E La Grange | 20 | Wife | — | Iowa |
| 79 | Cecilia Walker | 69 | Head | — | Tennessee |
| 80 | Edwin W Walker | 41 | Son | Chipper | Iowa |
Related Census Records
Pedigree Summary
Thomas + 2 siblings
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)