JC
James Costello — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Clinton-County, Iowa
Our Model Tree links this James Costello across the 1930 and 1940 US Censuses in Clinton-County, Iowa (XGBoost, ~Confirmed) — first a son (b.~1929), then head of a 7-person household.
Age 11
b. ~1929
Male
Son
Born: Iowa
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Clinton-County, Iowa |
| Surname | Costello |
| Given Name | James J. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Waterford township |
| 1935 Residence (County) | Clinton |
| Additional Details | |
| Highest Grade | G 5 |
| 1935 Residence | Same House |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Township / Ward | Waterford Township |
| Est. Birth Year | ~1929 |
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.
7 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to James | Age | Birth yr |
|---|---|---|---|---|
| Eileen Costello | Daughter | — | 8 | ~1932 |
| Valery Costello | Head | — | 38 | ~1902 |
| L Costello | Daughter | — | 7 | ~1933 |
| Ella Costello | Spouse | — | 38 | ~1902 |
| Gilbert Costello | Son | — | 4 | ~1936 |
| Michael Costello | Son | — | 10 | ~1930 |
| James Costello | Son | — | 11 | ~1929 |
Census Appearances
1930
Clinton, Iowa
Son, age 1
Clinton, Iowa · implied b. ~1929 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Costello |
| Given Name | James J. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 1 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Illinois |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Clinton-County, Iowa
Son, age 11
Clinton-County, Iowa · implied b. ~1929 — 7 household members
| Surname | Costello |
| Given Name | James J. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 11 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Waterford township |
| 1935 Residence (County) | Clinton |
| Highest Grade | G 5 |
| 1935 Residence | Same House |
| 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 James Costello across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
James Costello
Son · 1940 · age 11 · b. ~1929 · Iowa
★ You are viewing this record
Sibling
Gilbert Costello
Sibling · 1940 · age 4
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Michael Costello
Sibling · 1940 · age 10
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
L Costello
Sibling · 1940 · age 7
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Eileen Costello
Sibling · 1940 · 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
1940 US Federal Census — Clinton-County, Iowa
Open full size
1940 US Federal Census — Clinton-County, Iowa
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01151-00396)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | C. Henry Williams | 55 | Head | Farmer | Iowa |
| 42 | Inge J. Williams | 52 | Wife | — | Germany |
| 43 | Charles H. Williams | 19 | Son | Laborer | Iowa |
| 44 | Arthur J. Grieve | 42 | Head | Farmer | Iowa |
| 45 | Martha B. Grieve | 38 | Wife | — | Iowa |
| 46 | Arthur J. Jr. Grieve | 11 | Son | — | Iowa |
| 47 | Thomas J. Peterson | 14 | Nephew | — | Iowa |
| 48 | Ernest W. Peterson | 11 | Nephew | — | Iowa |
| 49 | Harry L. Collins | 51 | Head | Farmer | Iowa |
| 50 | Jennie L. Collins | 48 | Wife | — | Iowa |
| 51 | Robert J. Collins | 19 | Son | Laborer | Iowa |
| 52 | Ora E. Hood | 54 | Head | Farmer | Iowa |
| 53 | Leola M. Hood | 49 | Wife | — | Iowa |
| 54 | Ora J. Jr. Hood | 17 | Son | Laborer | Iowa |
| 55 | Marvin N. Hood | 15 | Son | Laborer | Iowa |
| 56 | Melvin B. Hood | 15 | Son | Laborer | Iowa |
| 57 | William E. Spain | 65 | Head | Farmer | Iowa |
| 58 | L. Marie Spain | 33 | Daughter | — | Iowa |
| 59 | Line Vacant | None | — | — | — |
| 60 | John A. Mcquistion | 39 | Head | Farmer | Iowa |
| 61 | Eva C. Mcquistion | 33 | Wife | — | Iowa |
| 62 | Wayne J. Mcquistion | 3 | Son | — | Iowa |
| 63 | William H. Wiese | 40 | Head | Farmer | Iowa |
| 64 | Dettal L. Wiese | 30 | Wife | — | Iowa |
| 65 | Roland H. Wiese | 4 | Son | — | Iowa |
| 66 | Harry F. Wiese | 2 | Son | — | Iowa |
| 67 | Cyril De Vrieze | 38 | Hired Hand | Laborer | Belgium |
| 68 | Antone F. Roethlisberger|Roethlis | 44 | Head | Farmer | Iowa |
| 69 | Mary C. Roethlisberger|Roethlis | 50 | Wife | — | Kansas |
| 70 | Bernadine C. Roethlisberger|Roethlis | 10 | Daughter | — | Iowa |
| 71 | Michael J. Costello | 48 | Head | Farmer | Iowa |
| 72 | Genevieve Costello | 40 | Wife | — | Iowa |
| 73 | Vincent Donegan | 15 | Lodger | — | Iowa |
| 74 | Valery J. Costello | 38 | Head | Farmer | Iowa |
| 75 | Ella B. Costello | 38 | Wife | — | Illinois |
| 76 | James J. Costello THIS PERSON | 11 | Son | — | Iowa |
| 77 | Michael L. Costello | 10 | Son | — | Iowa |
| 78 | Gilbert C. Costello | 4 | Son | — | Iowa |
| 79 | Eileen F. Costello | 8 | Daughter | — | Iowa |
| 80 | L. Marie Costello | 7 | 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)