MW
Mary Williamson — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Clayton-County, Iowa
Our Model Tree links this Mary Williamson across the 1920, 1930 and 1940 US Censuses in Clayton-County, Iowa (XGBoost, ~Confirmed) — first a head (b.~1849), then head of a 3-person household.
Age 91
b. ~1849
Female
Head
Born: New York
Widowed
1940 Census Record Details
| Census Year | 1940 |
| Location | Clayton-County, Iowa |
| Surname | Williamson |
| Given Name | Mary A. |
| Relationship to Head | Head |
| Sex | F |
| Color / Race | White |
| Age | 91 |
| Marital Status | Widowed |
| Birthplace | New York |
| 1935 Residence (City) | McGregor |
| 1935 Residence (County) | Clayton |
| Additional Details | |
| Income (1939) | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same house |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
| Township / Ward | Mcgregor |
| Est. Birth Year | ~1849 |
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 Mary | Age | Birth yr |
|---|---|---|---|---|
| Harriet Condon | Daughter | — | 69 | ~1871 |
| Mary Williamson | Head | — | 91 | ~1849 |
| Milo Williamson | Son | — | 57 | ~1883 |
Census Appearances
1920
Clayton, Iowa
Other, age 72
Clayton, Iowa · implied b. ~1848 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Williamson |
| Given Name | Mary |
| Relationship to Head | Sister |
| Sex | F |
| Color / Race | White |
| Age | 72 |
| Marital Status | Widowed |
| Birthplace | New York |
| Father's Birthplace | New York |
| Mother's Birthplace | New York |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
1930
Clayton, Iowa
Other, age 81
Clayton, Iowa · implied b. ~1849 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Williamson |
| Given Name | Mary |
| Relationship to Head | Head-H |
| Sex | F |
| Color / Race | White |
| Age | 81 |
| Marital Status | Widowed |
| Birthplace | New York |
| Age at First Marriage | 21 |
| Father's Birthplace | New York |
| Mother's Birthplace | New York |
| Can Read/Write | Yes |
| Home Owned/Rented | O |
| Home Value / Rent | 4000 |
| Radio Set | R |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
1940
Clayton-County, Iowa
Head, age 91
Clayton-County, Iowa · implied b. ~1849 — 3 household members
| Surname | Williamson |
| Given Name | Mary A. |
| Relationship to Head | Head |
| Sex | F |
| Color / Race | White |
| Age | 91 |
| Marital Status | Widowed |
| Birthplace | New York |
| 1935 Residence (City) | McGregor |
| 1935 Residence (County) | Clayton |
| Income (1939) | 0 |
| Highest Grade | No 8 |
| 1935 Residence | Same house |
| Birth State | New York |
| Birth Country | United States |
| Birthplace (normalized) | new york |
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 Williamson across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage.
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This person
Anchor record
Mary Williamson
Head · 1940 · age 91 · b. ~1849 · 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 — Clayton-County, Iowa
Open full size
1940 US Federal Census — Clayton-County, Iowa
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01149-00485)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Milo Peterson | 31 | Head | Custodian | Iowa |
| 42 | Irene Peterson | 30 | Wife | — | Iowa |
| 43 | John Peterson | 4 | Son | — | Iowa |
| 44 | J. L. Dowsing | 51 | Head | Salesman | Iowa |
| 45 | Lola Dowsing | 49 | Wife | — | Arkansas |
| 46 | Harold Dowsing | 25 | Son | Clerk | Iowa |
| 47 | Lyall H. Mitchell | 36 | Head | Agric. Engin. | Iowa |
| 48 | Helen Mitchell | 34 | Wife | — | Illinois |
| 49 | Kent Mitchell | 5 | Son | — | Illinois |
| 50 | Dale H. Mitchell | 1 | Son | — | Iowa |
| 51 | Gerald Connell | 51 | Head | Watchman | Iowa |
| 52 | Ethel V. Connell | 39 | Wife | — | Wisconsin |
| 53 | John Connell | 15 | Son | Paper Carrier | Iowa |
| 54 | William Connell | 13 | Son | Delivery Boy | Iowa |
| 55 | Jo Nan Connell | 10 | Daughter | — | Iowa |
| 56 | Florence Woods | 59 | Head | — | Wisconsin |
| 57 | Buck, Carrie Woods | 78 | Mother | — | Iowa |
| 58 | George R. Drygg | 35 | Head | Buyer | Iowa |
| 59 | Marjorie Drygg | 28 | Wife | — | Iowa |
| 60 | Karen Drygg | 1 | Daughter | — | Iowa |
| 61 | Peter E. Mcguire | 40 | Head | Relief Clerk | Iowa |
| 62 | Mildred Mcguire | 35 | Wife | — | Iowa |
| 63 | William T. Robinson | 66 | Head | — | Iowa |
| 64 | Mary L. Robinson | 66 | Wife | Laundress | Sweden |
| 65 | J. J. Goheen | 58 | Head | Cashier | Iowa |
| 66 | Antha Goheen | 54 | Wife | — | Iowa |
| 67 | John J. Goheen | 16 | Son | Clerk | Iowa |
| 68 | W. A. C. Thrill | 79 | Head | Novelty Shop | Ohio |
| 69 | Georgia Thrill | 74 | Wife | — | Ohio |
| 70 | Russell Frankson | 24 | Head | Appren. Lineman | Minnesota |
| 71 | Betty Lou Frankson | 23 | Wife | — | Minnesota |
| 72 | James Frankson | 4 | Son | — | Minnesota |
| 73 | Corrine Lou Frankson | 3 | Daughter | — | Minnesota |
| 74 | Mary A. Williamson THIS PERSON | 91 | Head | — | New York |
| 75 | Milo Williamson | 57 | Son | — | Iowa |
| 76 | Harriet Ruth Condon | 69 | Daughter | — | New York |
| 77 | H. A. Seybert | 33 | Head | Electrician | Iowa |
| 78 | Alice Seybert | 32 | Wife | — | Iowa |
| 79 | Jane Seybert | 14 | Daughter | — | Iowa |
| 80 | Barbara Seybert | 10 | 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)