JM
James Mack — 1940 US Census Record
Linked across censuses1940 United States Federal Census · Calhoun-County, Iowa
Our Model Tree links this James Mack across the 1930 and 1940 US Censuses in Calhoun-County, Iowa (XGBoost, ~Confirmed) — first a son (b.~1926), then head of a 9-person household.
Age 14
b. ~1926
Male
Son
Born: Iowa
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Calhoun-County, Iowa |
| Surname | Mack |
| Given Name | James |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Butler Twp |
| 1935 Residence (County) | Calhoun |
| Additional Details | |
| Highest Grade | No 7 |
| 1935 Residence | Same house |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
| Township / Ward | Butler Twp |
| Est. Birth Year | ~1926 |
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 1940 census.
| Name | Relation to head | Relative to James | Age | Birth yr |
|---|---|---|---|---|
| Joann Mack | Daughter | — | 8 | ~1932 |
| Ernest Mack | Head | — | 59 | ~1881 |
| Ida Mack | Spouse | — | 49 | ~1891 |
| Paul Mack | Son | — | 18 | ~1922 |
| William Mack | Other | — | 62 | ~1878 |
| Martin Mack | Son | — | 22 | ~1918 |
| Herman Mack | Son | — | 16 | ~1924 |
| James Mack | Son | — | 14 | ~1926 |
| Lois Mack | Daughter | — | 12 | ~1928 |
Census Appearances
1930
Calhoun, Iowa
Son, age 4
Calhoun, Iowa · implied b. ~1926 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Mack |
| Given Name | James |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 4 |
| Marital Status | Single |
| Birthplace | Iowa |
| Father's Birthplace | Iowa |
| Mother's Birthplace | Iowa |
| Birth State | Iowa |
| Birth Country | United States |
| Birthplace (normalized) | iowa |
1940
Calhoun-County, Iowa
Son, age 14
Calhoun-County, Iowa · implied b. ~1926 — 9 household members
| Surname | Mack |
| Given Name | James |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 14 |
| Marital Status | Single |
| Birthplace | Iowa |
| 1935 Residence (City) | Butler Twp |
| 1935 Residence (County) | Calhoun |
| Highest Grade | No 7 |
| 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 Mack across 2 US Census years (1930 and 1940) in 2 locations, using XGBoost record linkage.
Show:
This person
Anchor record
James Mack
Son · 1940 · age 14 · b. ~1926 · Iowa
★ You are viewing this record
Sibling
Herman Mack
Sibling · 1940 · age 16
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Martin Mack
Sibling · 1940 · age 22
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Lois Mack
Sibling · 1940 · age 12
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Paul Mack
Sibling · 1940 · age 18
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Joann Mack
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 — Calhoun-County, Iowa
Open full size
1940 US Federal Census — Calhoun-County, Iowa
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-01144-00051)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Eunice Mack | 8 | Daughter | — | Iowa |
| 42 | Ernest G. Mack | 59 | Head | Farmer | Iowa |
| 43 | Ida Mack | 49 | Wife | — | Iowa |
| 44 | Martin Mack | 22 | Son | Farm Laborer | Iowa |
| 45 | Paul Mack | 18 | Son | Attendant | Iowa |
| 46 | Herman Mack | 16 | Son | — | Iowa |
| 47 | James Mack THIS PERSON | 14 | Son | — | Iowa |
| 48 | Lois Mack | 12 | Daughter | — | Iowa |
| 49 | Joann Mack | 8 | Daughter | — | Iowa |
| 50 | William J. Mack | 62 | Brother | Farm Laborer | Iowa |
| 51 | William Dettman | 48 | Head | Farmer | Iowa |
| 52 | Gertrude Dettman | 39 | Wife | — | Iowa |
| 53 | Marshall Dettman | 17 | Son | — | Iowa |
| 54 | Marlene Dettman | 8 | Daughter | — | Iowa |
| 55 | Joseph Patterson | 31 | Head | Farmer | Iowa |
| 56 | Dora Patterson | 30 | Wife | — | Iowa |
| 57 | Lou Jeane Patterson | 9 | Daughter | — | Iowa |
| 58 | Mont Percy Patterson | 18 | Boarder | Farm Laborer | Iowa |
| 59 | Albert Gregg | 62 | Head | Proprietor | Michigan |
| 60 | Josephine Gregg | 42 | Wife | — | New York |
| 61 | James Gregg | 15 | Son | — | Iowa |
| 62 | Marilyn Gregg | 13 | Daughter | — | Iowa |
| 63 | Earl Babb | 28 | Head | Farmer | Wisconsin |
| 64 | Ann Babb | 26 | Wife | — | Iowa |
| 65 | Beverly Babb | 6 | Daughter | — | Iowa |
| 66 | Gerhard Johnson | 38 | Head | Farmer | Illinois |
| 67 | Sophia Johnson | 36 | Wife | — | Iowa |
| 68 | Lucille Johnson | 10 | Daughter | — | Iowa |
| 69 | William Johnson | 4 | Son | — | Iowa |
| 70 | John F. Stein | 30 | Head | Farmer | Iowa |
| 71 | Abbie Stein | 25 | Wife | — | Iowa |
| 72 | Helen Stein | 4 | Daughter | — | Iowa |
| 73 | Lawrence Stein | 2 | Son | — | Iowa |
| 74 | Harold Whitmore | 24 | Hired Hand | Farmer | Iowa |
| 75 | John Kottman | 74 | Head | — | Illinois |
| 76 | John R. Kottman | 46 | Son | Farmer | Illinois |
| 77 | Edward Kottman | 34 | Son | Farmer | Illinois |
| 78 | Carl Kottman | 32 | Son | Farmer | Nebraska |
| 79 | Bernice Kottman | 24 | Daughter-in-law | — | Iowa |
| 80 | Ernest Morwitzer | 39 | Head | Farmer | 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)