MC
Mary Costello — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Cook-County, Illinois
Our Model Tree links this Mary Costello across the 1920, 1930 and 1940 US Censuses in Cook-County, Illinois (XGBoost, ~Confirmed) — first a spouse (b.~1886), then head of a 3-person household.
Age 54
b. ~1886
Female
Spouse
Born: England
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Cook-County, Illinois |
| Surname | Costello |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 54 |
| Marital Status | Married |
| Birthplace | England |
| 1935 Residence (City) | Chicago city |
| 1935 Residence (County) | Cook |
| Naturalization Status | Naturalized |
| Additional Details | |
| Income (1939) | 0 |
| Highest Grade | H 2 |
| 1935 Residence | Same House |
| Birth Country | England |
| Birthplace (normalized) | england |
| Township / Ward | Chicago City |
| Est. Birth Year | ~1886 |
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 |
|---|---|---|---|---|
| William Costello | Head | — | 53 | ~1887 |
| William Costello | Son | — | 17 | ~1923 |
| Mary Costello | Spouse | — | 54 | ~1886 |
Census Appearances
1920
Cook, Illinois
Spouse, age 30
Cook, Illinois · implied b. ~1890 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Costello |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 30 |
| Marital Status | Married |
| Birthplace | England |
| Year of Immigration | 1915 |
| Naturalization Status | Alien |
| Father's Birthplace | England |
| Mother's Birthplace | England |
| Occupation | none |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Mother Tongue | English |
| Birth Country | England |
| Birthplace (normalized) | england |
1930
Cook, Illinois
Spouse, age 40
Cook, Illinois · implied b. ~1890 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Castello |
| Given Name | Mary A. |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 40 |
| Marital Status | Married |
| Birthplace | England |
| Naturalization Status | Alien |
| Year of Immigration | 1915 |
| Age at First Marriage | 28 |
| Father's Birthplace | England |
| Mother's Birthplace | England |
| Can Read/Write | Yes |
| Mother Tongue | English |
| Birth Country | England |
| Birthplace (normalized) | england |
1940
Cook-County, Illinois
Spouse, age 54
Cook-County, Illinois · implied b. ~1886 — 3 household members
| Surname | Costello |
| Given Name | Mary |
| Relationship to Head | Wife |
| Sex | F |
| Color / Race | White |
| Age | 54 |
| Marital Status | Married |
| Birthplace | England |
| 1935 Residence (City) | Chicago city |
| 1935 Residence (County) | Cook |
| Naturalization Status | Naturalized |
| Income (1939) | 0 |
| Highest Grade | H 2 |
| 1935 Residence | Same House |
| Birth Country | England |
| Birthplace (normalized) | england |
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 Costello 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 Costello
Spouse · 1940 · age 54 · b. ~1886 · Illinois
★ You are viewing this record
Confirmed / household (~0.90+)
Probable / derived (~0.65–0.89)
Candidate (<0.65, unverified)
Original Census Page
1940 US Federal Census — Cook-County, Illinois
Open full size
1940 US Federal Census — Cook-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00989-00652)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Amanda Hurwitz | 43 | Wife | — | Illinois |
| 42 | Aletha Hurwitz | 14 | Daughter | — | Illinois |
| 43 | George Kornblum | 55 | Head | Salesman | Germany |
| 44 | Myrtle Kornblum | 44 | Wife | — | Illinois |
| 45 | Howard Kornblum | 33 | Son | Milkman | Illinois |
| 46 | William Street | 21 | Son | Nickel Plate | Illinois |
| 47 | Roger Street | 19 | Stepson | Nickel Plate | Illinois |
| 48 | Emma Bistrom | 60 | Head | Janitress | Sweden |
| 49 | Nels Bistrom | 29 | Son | Elevator Man | Illinois |
| 50 | Arthur J. Klotz | 54 | Head | Wholesale Meat | Illinois |
| 51 | Minna C. Klotz | 51 | Wife | — | Illinois |
| 52 | Cleo Klotz | 18 | Daughter | Page Girl | Illinois |
| 53 | Ida M. Leathers | 70 | Head | — | Pennsylvania |
| 54 | James W. Leathers | 42 | Son | Stock Keeper | Pennsylvania |
| 55 | Burles N. Wendell | 32 | Daughter | City Nurse | Pennsylvania |
| 56 | Axel Thorsen | 58 | Head | Carpenter | Norway |
| 57 | Nora Thorsen | 50 | Wife | — | Norway |
| 58 | Mabel Thorsen | 25 | Daughter | Stenographer | Illinois |
| 59 | Dorothy Thorsen | 22 | Daughter | Clerk | Illinois |
| 60 | Lois Thorsen | 19 | Daughter | — | Minnesota |
| 61 | Allen Thorsen | 17 | Son | — | Minnesota |
| 62 | Betty Thorsen | 15 | Daughter | — | Minnesota |
| 63 | Charles Nestel | 49 | Head | Lithographer | Germany |
| 64 | Marie Nestel | 42 | Wife | — | Illinois |
| 65 | Charles Jr. Nestel | 19 | Son | — | Ohio |
| 66 | Callie Nestel | 18 | Daughter | Stenographer | Illinois |
| 67 | Eunice Nestel | 14 | Daughter | — | Illinois |
| 68 | Mary Schwartz | 78 | Mother-in-law | — | Illinois |
| 69 | Robert Schumm | 34 | Roomer | Draftsman | Michigan |
| 70 | Bernard Reissing | 49 | Head | Machinist | Germany |
| 71 | Clara Reissing | 44 | Wife | Maid | Germany |
| 72 | Lillian Reissing | 13 | Daughter | — | Illinois |
| 73 | William Costello | 53 | Head | Deputy Clerk | Illinois |
| 74 | Mary Costello THIS PERSON | 54 | Wife | — | England |
| 75 | William J. Costello | 17 | Son | — | Illinois |
| 76 | John Hadycki | 44 | Head | Painter | Poland |
| 77 | Anna Hadycki | 37 | Wife | — | Poland |
| 78 | Richard Hadycki | 17 | Son | — | Illinois |
| 79 | Alan Speiss | 26 | Head | Traffic Manager | Illinois |
| 80 | Marie Speiss | 26 | Wife | Switchboard Oper. | Nebraska |
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)