MG
Mary Grace — 1940 US Census Record
Linked across censuses1940 United States Federal Census · St.-Louis-County, Missouri
Our Model Tree links this Mary Grace across the 1930 and 1940 US Censuses in St.-Louis-County, Missouri (XGBoost, ~Confirmed) — first a daughter (b.~1923), then head of a 16-person household.
Age 17
b. ~1923
Female
Daughter
Born: Missouri
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | St.-Louis-County, Missouri |
| Surname | Grace |
| Given Name | Mary C. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 17 |
| Marital Status | Single |
| Birthplace | Missouri |
| 1935 Residence (City) | University City |
| 1935 Residence (County) | St. Louis |
| Additional Details | |
| Income (1939) | 0 |
| Highest Grade | H-4 |
| 1935 Residence | Missouri |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
| Township / Ward | Richmond Heights |
| Est. Birth Year | ~1923 |
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.
16 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Mary | Age | Birth yr |
|---|---|---|---|---|
| Walter Genis | Son | — | 23 | ~1917 |
| Robert Leahy | Son | — | 2 | ~1938 |
| Maria Leahy | Spouse | — | 25 | ~1915 |
| Frances Davis | Other | — | 72 | ~1868 |
| Ruby Blessing | Other | — | 63 | ~1877 |
| Josephine Sullivan | Other | — | 68 | ~1872 |
| Thelma Leonard | Other | — | 20 | ~1920 |
| Anna Miller | Other | — | 59 | ~1881 |
| Joseph Leahy | Head | — | 29 | ~1911 |
| Mary Grace | Daughter | — | 17 | ~1923 |
| Margaret Gorman | Other | — | 45 | ~1895 |
| Mary Brodigan | Other | — | 61 | ~1879 |
| Gladys Partridge | Other | — | 19 | ~1921 |
| Jack Witzel | Son | — | 15 | ~1925 |
| John Gorman | Son | — | 15 | ~1925 |
| Stanley Barrett | Son | — | 18 | ~1922 |
Census Appearances
1930
St Louis, …
Daughter, age 6
St Louis, Missouri · implied b. ~1924 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Grace |
| Given Name | Mary L |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 6 |
| Marital Status | Single |
| Birthplace | Missouri |
| Father's Birthplace | Missouri |
| Mother's Birthplace | New York |
| Can Read/Write | No |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
1940
St.-Louis-County, Missouri
Daughter, age 17
St.-Louis-County, Missouri · implied b. ~1923 — 16 household members
| Surname | Grace |
| Given Name | Mary C. |
| Relationship to Head | Daughter |
| Sex | F |
| Color / Race | White |
| Age | 17 |
| Marital Status | Single |
| Birthplace | Missouri |
| 1935 Residence (City) | University City |
| 1935 Residence (County) | St. Louis |
| Income (1939) | 0 |
| Highest Grade | H-4 |
| 1935 Residence | Missouri |
| Birth State | Missouri |
| Birth Country | United States |
| Birthplace (normalized) | missouri |
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 Grace across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
Mary Grace
Daughter · 1940 · age 17 · b. ~1923 · Missouri
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Sibling
Robert Leahy
Sibling · 1940 · age 2
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
John Gorman
Sibling · 1940 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Stanley Barrett
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Walter Genis
Sibling · 1940 · age 23
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Jack Witzel
Sibling · 1940 · age 15
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 — St.-Louis-County, Missouri
Open full size
1940 US Federal Census — St.-Louis-County, Missouri
Page Contents
34 people indexed on this census page (nara:1940:m-t0627-02150-01088)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Joseph M. Leahy | 29 | Head | Manager | Missouri |
| 2 | Maria Adriana Leahy | 25 | Wife | — | Missouri |
| 3 | Robert J. Leahy | 2 | Son | — | Missouri |
| 4 | Mary Brodigan | 61 | Mother | Matron | Illinois |
| 5 | Josephine Sullivan | 68 | Aunt | — | Illinois |
| 6 | Thelma Leonard | 20 | Lodger | Stenographer | Missouri |
| 7 | Gladys Partridge | 19 | Niece | New Worker | Missouri |
| 8 | Walter Genis | 23 | Son | Collector | Missouri |
| 9 | John Jr. Gorman | 15 | Son | — | Missouri |
| 10 | Margaret A. Gorman | 45 | Sister | Millinery & Ready-To-Wear Shop | Missouri |
| 11 | Anna Miller | 59 | Housekeeper | Housekeeper | Mississippi |
| 12 | Mary C. Grace THIS PERSON | 17 | Daughter | — | Missouri |
| 13 | Jack Witzel | 15 | Son | — | Missouri |
| 14 | Ruby Blessing | 63 | Mother | — | Iowa |
| 15 | Frances Davis | 72 | Mother-in-law | — | Iowa |
| 16 | Stanley Barrett | 18 | Son | — | Missouri |
| 17 | Edward M. Brewer | 50 | Head | Truck Driver | Missouri |
| 18 | Nora Brewer | 43 | Wife | — | Indiana |
| 19 | Mary Brewer | 17 | Daughter | Sales Girl | Missouri |
| 20 | Oliver Brewer | 14 | Son | — | Missouri |
| 21 | Frances Brewer | 13 | Daughter | — | Missouri |
| 22 | Walter Brewer | 11 | Son | — | Missouri |
| 23 | Arthur Brewer | 4 | Son | — | Missouri |
| 24 | Ruth Leonhard | 24 | Servant | Servant | Missouri |
| 25 | Hilmer Horn | 26 | Lodger | Office Clerk | Missouri |
| 26 | Walter Horn | 23 | Lodger Brother | — | Missouri |
| 27 | John J. Kastervitz | 12 | Son | — | Missouri |
| 28 | Viola M. Genge | 25 | Niece | Time Keeper | Maryland |
| 29 | Selena C. Mast | 48 | Sister | Office Clerk | Arkansas |
| 30 | Daisy Snedeger | 49 | Mother-in-law | Housekeeper | Kentucky |
| 31 | Fred Mayer | 28 | Brother-in-law | Delivery | Missouri |
| 32 | Anna Mayer | 67 | Mother-in-law | — | Germany |
| 33 | Dorothy Connors | 24 | Lodger | Dictaphone Operator | Missouri |
| 34 | John P. Fortney | 5 | Lodger | Seaman | Missouri |
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)