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Mary Mcmahon — 1930 US Census Record
Linked across censuses1930 United States Federal Census · Dubuque, Iowa
Our Model Tree links this Mary Mcmahon across the 1920 and 1930 US Censuses in Dubuque, Iowa (XGBoost, ~Confirmed) — first a daughter (b.~1917), then head of a 9-person household.
Age 13
b. ~1917
Female
Daughter
Born: Iowa
Single
1930 Census Record Details
| Census Year | 1930 |
| Location | Dubuque, Iowa |
| Surname | McMahon |
| Given Name | Mary G. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Additional Details | |
| Can Read/Write | Yes |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Township / Ward | Dubuque City |
| Est. Birth Year | ~1917 |
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.
9 people recorded at the same address in the 1930 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Mary Mcmahon | Daughter | — | 13 | ~1917 |
| Joseph Mcmahon | Head | — | 49 | ~1881 |
| Genevieve Mcmahon | Other | — | 44 | ~1886 |
| Robert Mcmahon | Son | — | 15 | ~1915 |
| Joseph Mcmahon | Son | — | 8 | ~1922 |
| Harold Mcmahon | Son | — | 17 | ~1913 |
| Clarence Mcmahon | Son | — | 16 | ~1914 |
| Maurice Mcmahon | Son | — | 14 | ~1916 |
| David Mcmahon | Son | — | 11 | ~1919 |
Census Appearances
1920
Dubuque, Iowa
Daughter, age 2
Dubuque, Iowa · implied b. ~1918 — 8 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | McMahon |
| Given Name | Mary |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 2 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1930
Dubuque, Iowa
Daughter, age 13
Dubuque, Iowa · implied b. ~1917 — 9 household members
| Surname | McMahon |
| Given Name | Mary G. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 13 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Can Read/Write | Yes |
| 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 Mary Mcmahon across 2 US Census years (1920 and 1930) in Dubuque, Iowa, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Mcmahon
Daughter · 1930 · age 13 · b. ~1917 · Iowa
★ You are viewing this record
Sibling
David Mcmahon
Sibling · 1930 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Robert Mcmahon
Sibling · 1930 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Harold Mcmahon
Sibling · 1930 · age 17
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Clarence Mcmahon
Sibling · 1930 · age 16
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Maurice Mcmahon
Sibling · 1930 · age 14
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joseph Mcmahon
Sibling · 1930 · age 8
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
1930 US Federal Census — Dubuque, Iowa
Open full size
1930 US Federal Census — Dubuque, Iowa
Page Contents
50 people indexed on this census page (ia:1930:iowacensus00reel653:1086)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Braem Randall | 3 | Son | — | Iowa |
| 2 | John J. Prendergast | 54 | Head | Salesman | Nebraska |
| 3 | Blanche Prendergast | 49 | Wife-H | Teacher | Nebraska |
| 4 | Clare Prendergast | 26 | Daughter | — | Nebraska |
| 5 | Honora Prendergast | 22 | Daughter | — | Nebraska |
| 6 | Mary Prendergast | 18 | Daughter | — | Nebraska |
| 7 | Edwin T. Ley | 29 | Head | Ice Cream Maker | Iowa |
| 8 | Louise Ley | 29 | Wife-H | — | Iowa |
| 9 | Dallas A. Ley | 8 | Daughter | — | Iowa |
| 10 | Jack G. Ley | 6 | Son | — | Iowa |
| 11 | Paul Thul | 72 | Head | — | Germany |
| 12 | Della C. Thul | 30 | Daughter | — | Iowa |
| 13 | Edna M. Thul | 26 | Daughter | — | Iowa |
| 14 | James H. Delaney | 41 | Head | Postal Clerk | Iowa |
| 15 | Edna Delaney | 44 | Wife-H | — | Iowa |
| 16 | Walter F. Jaeger | 45 | Head | Conductor | Iowa |
| 17 | Mathilda Jaeger | 40 | Wife-H | — | Iowa |
| 18 | Alvin A. Jaeger | 17 | Son | — | Iowa |
| 19 | Leonard Jaeger | 16 | Son | — | Iowa |
| 20 | Anna M. Jaeger | 14 | Daughter | — | Iowa |
| 21 | Helen G. Jaeger | 11 | Daughter | — | Iowa |
| 22 | Mary L. Jaeger | 6 | Daughter | — | Iowa |
| 23 | Florence F. Jaeger | 3 | Daughter | — | Iowa |
| 24 | Joseph A. Mcmahon | 49 | Head | Realtor | Iowa |
| 25 | Genevieve M. Mcmahon | 44 | Wife-H | — | Iowa |
| 26 | Harold B. Mcmahon | 17 | Son | — | Iowa |
| 27 | Clarence D. Mcmahon | 16 | Son | — | Iowa |
| 28 | Robert J. Mcmahon | 15 | Son | — | Iowa |
| 29 | Maurice Mcmahon | 14 | Son | — | Iowa |
| 30 | Mary G. Mcmahon THIS PERSON | 13 | Daughter | — | Iowa |
| 31 | David L. Mcmahon | 11 | Son | — | Iowa |
| 32 | Joseph F. Mcmahon | 8 | Son | — | Iowa |
| 33 | Henry Richman | 46 | Head | Boiler Repairer | Illinois |
| 34 | Caroline Richman | 44 | Wife-H | — | Iowa |
| 35 | Viola Richman | 20 | Daughter | Helper | Iowa |
| 36 | Leona Richman | 18 | Daughter | — | Iowa |
| 37 | Lawrence Mcintyre | 55 | Head | Carpenter | Iowa |
| 38 | Carrie G. Mcintyre | 46 | Wife-H | — | Iowa |
| 39 | Owen Mccann | 60 | Head | Laborer | Iowa |
| 40 | William B. O'Neill | 37 | Head | — | Iowa |
| 41 | Ella O'Neill | 35 | Wife-H | — | Iowa |
| 42 | Donald O'Neill | 9 | Son | — | Iowa |
| 43 | Helen O'Neill | 7 | Daughter | — | Iowa |
| 44 | Raymond O'Neill | 3 | Son | — | Iowa |
| 45 | Thomas Hanley | 72 | Head | — | Iowa |
| 46 | Amelia Hanley | 74 | Wife-H | — | Iowa |
| 47 | Mary Hanley | 32 | Daughter | Partner | Iowa |
| 48 | Eugene Siegert | 73 | Head | — | Germany |
| 49 | Anna B. Siegert | 64 | Wife-H | — | Bavaria |
| 50 | Edmund Siegert | 22 | Head | Accountant | Iowa |
About This Record & Model Tree
This record was independently indexed by YourRoots from the 1930 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)