HC
Harold Clark — 1940 US Census Record
Model Tree available1940 United States Federal Census · Winnebago-County, Illinois
Our Model Tree links this Harold Clark across the 1920, 1930 and 1940 US Censuses in Winnebago-County, Illinois (XGBoost, ~Confirmed), with identified parents Lou & Noah — first a son (b.~1910), then head of a 4-person household.
Age 30
b. ~1910
Male
Son
Born: Illinois
Single
1940 Census Record Details
| Census Year | 1940 |
| Location | Winnebago-County, Illinois |
| Surname | Clark |
| Given Name | Harold D. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 30 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Rockford City |
| 1935 Residence (County) | WINNEBAGO |
| Additional Details | |
| Occupation | Draftsman |
| Industry | Machine Tool Factory |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 1400 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same House |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
| Occupation | Draftsman |
| Township / Ward | Rockford City |
| Est. Birth Year | ~1910 |
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.
4 people recorded at the same address in the 1940 census.
| Name | Relation to head | Relative to Harold | Age | Birth yr |
|---|---|---|---|---|
| Elizabeth Clark | Head | — | 68 | ~1872 |
| Starr Whitley | Other | — | 24 | ~1916 |
| Harold Clark | Son | — | 30 | ~1910 |
| Clifford Henning | Other | — | 27 | ~1913 |
Census Appearances
1920
Winnebago, Illinois
Son, age 9
Winnebago, Illinois · implied b. ~1911 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Clark |
| Given Name | Harold |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 9 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Michigan |
| Mother's Birthplace | England |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1930
Winnebago, Illinois
Son, age 20
Winnebago, Illinois · implied b. ~1910 — 5 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Clark |
| Given Name | Harold S. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 20 |
| Marital Status | Single |
| Birthplace | Illinois |
| Father's Birthplace | Michigan |
| Mother's Birthplace | England |
| Occupation | Machinist |
| Industry | Machine Shop |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
1940
Winnebago-County, Illinois
Son, age 30
Winnebago-County, Illinois · implied b. ~1910 — 4 household members
| Surname | Clark |
| Given Name | Harold D. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 30 |
| Marital Status | Single |
| Birthplace | Illinois |
| 1935 Residence (City) | Rockford City |
| 1935 Residence (County) | WINNEBAGO |
| Occupation | Draftsman |
| Industry | Machine Tool Factory |
| Class of Worker | PW |
| Hours Worked | 40 |
| Income (1939) | 1400 |
| Highest Grade | Hs 4 |
| 1935 Residence | Same House |
| Birth State | Illinois |
| Birth Country | United States |
| Birthplace (normalized) | illinois |
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 Harold Clark across 3 US Census years (1920, 1930 and 1940) in 2 locations, using XGBoost record linkage. Identified parents: father Lou Clark (~0.92 confidence) and father Noah Clark (~0.92 confidence) and mother Elizabeth Clark (~0.92 confidence). The pedigree spans 1 generation with 3 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Lou Clark
b. ~1867
Source father
● Household
· direct · ~0.92
Father
Noah Clark
b. ~1867
Source father
● Household
· direct · ~0.92
Mother
Elizabeth Clark
b. ~1872
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Harold Clark
Son · 1940 · age 30 · b. ~1910 · 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 — Winnebago-County, Illinois
Open full size
1940 US Federal Census — Winnebago-County, Illinois
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-00913-00901)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Walter F. Niesman | 50 | Head | Proprietor | Wisconsin |
| 42 | Hazel E. Niesman | 46 | Wife | — | Illinois |
| 43 | Lorraine C. Niesman | 24 | Daughter | Registered Nurse | Illinois |
| 44 | Roger F. Niesman | 22 | Son | Machine Tender | Illinois |
| 45 | Lewis C. Spooner | 58 | Head | Machinist | Wisconsin |
| 46 | Agnes A. Spooner | 56 | Wife | — | Illinois |
| 47 | Robert L. Spooner | 20 | Son | Apprentice Machinist | Illinois |
| 48 | Lenore J. Spooner | 16 | Daughter | — | Illinois |
| 49 | Alvena B. Westberg | 46 | Sister-in-law | Stenographer | Illinois |
| 50 | Elizabeth G. Clark | 68 | Head | — | England |
| 51 | Harold D. Clark THIS PERSON | 30 | Son | Draftsman | Illinois |
| 52 | Clifford Henning | 27 | Lodger | Salesman | Wisconsin |
| 53 | Starr Whitley | 24 | Lodger | Salesman | Iowa |
| 54 | Charles A. Mosher | 73 | Head | — | Illinois |
| 55 | Ida M. Mosher | 71 | Wife | — | Illinois |
| 56 | Myron Boklund | 43 | Head | Mechanic | Wisconsin |
| 57 | Lola M. Boklund | 45 | Wife | — | Wisconsin |
| 58 | Dale M. Boklund | 19 | Son | Sales Clerk | Wisconsin |
| 59 | Robert N. Boklund | 11 | Son | — | Illinois |
| 60 | Marilyn K. Boklund | 9 | Daughter | — | Illinois |
| 61 | Kate Hinccicun | 74 | Mother-in-law | — | Wisconsin |
| 62 | John J. Dubin | 43 | Head | Cabinet Maker | Lithuania |
| 63 | Dorothy Anne Dubin | 17 | Daughter | — | Illinois |
| 64 | John Olson | 52 | Head | Inspector | Iowa |
| 65 | Tillie Olson | 49 | Wife | — | Iowa |
| 66 | Blanche Olson | 14 | Daughter | — | Minnesota |
| 67 | Mary R. Hills | 24 | Head | Teacher | Illinois |
| 68 | Winifred R. Hills | 66 | Mother | — | Illinois |
| 69 | Rebecca J. Wait | 60 | Head | — | Pennsylvania |
| 70 | Adelaide L. Diehl | 51 | Lodger | Practical Nurse | Minnesota |
| 71 | George E. Pollard | 35 | Head | Machinist | Illinois |
| 72 | Dorothy E. Pollard | 34 | Wife | — | Illinois |
| 73 | Edna B. Knight | 56 | Head | Registered Nurse | Illinois |
| 74 | Mary A. Knight | 85 | Mother | — | Vermont |
| 75 | Dolores Peterson | 11 | Ward | — | Wisconsin |
| 76 | Mertin Peterson | 8 | Ward | — | Wisconsin |
| 77 | David E. Emerson | 40 | Head | Lathe Hand | Illinois |
| 78 | Katharine E. Emerson | 39 | Wife | — | Illinois |
| 79 | Margaret K. Emerson | 18 | Daughter | Assembler | Illinois |
| 80 | Janet H. Emerson | 19 | Daughter | — | Illinois |
Related Census Records
Pedigree Summary
Harold
Gen 1 · 3 parents
~0.92
Max depth 4 (1900–1950 window)
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)