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Isaac Johnson — 1940 US Census Record
Model Tree available1940 United States Federal Census · Charleston-County, South Carolina
Our Model Tree links this Isaac Johnson across the 1910, 1920, 1930 and 1940 US Censuses in Charleston-County, South Carolina (XGBoost, ~Confirmed), with identified parents Isaac & James — first a head (b.~1910), then head of a 4-person household.
Age 30
b. ~1910
Male
Head
Born: South Carolina
Married
1940 Census Record Details
| Census Year | 1940 |
| Location | Charleston-County, South Carolina |
| Surname | Johnson |
| Given Name | Isaac |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | Black |
| Age | 30 |
| Marital Status | Married |
| Birthplace | South Carolina |
| 1935 Residence (City) | Charleston City |
| 1935 Residence (County) | Charleston |
| Additional Details | |
| Occupation | Laborer |
| Industry | Fertilizer Plant |
| Class of Worker | PW |
| Hours Worked | 55 |
| Income (1939) | 700 |
| Highest Grade | No 4 |
| 1935 Residence | Same place |
| Birth State | South Carolina |
| Birth Country | United States |
| Birthplace (normalized) | south carolina |
| Occupation | Laborer |
| Township / Ward | Charleston 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 Isaac | Age | Birth yr |
|---|---|---|---|---|
| Isaac Johnson | Head | — | 30 | ~1910 |
| Joe Johnson | Son | — | 3 | ~1937 |
| Willie Johnson | Son | — | 5 | ~1935 |
| Sarah Johnson | Spouse | — | 27 | ~1913 |
Census Appearances
1910
None, South …
Son, age 1
None, South Carolina · implied b. ~1909 — 3 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Johnson |
| Given Name | Isaac |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | Black |
| Age | 1 |
| Marital Status | Single |
| Birthplace | South Carolina |
| Father's Birthplace | South Carolina |
| Mother's Birthplace | South Carolina |
| Can Read | No |
| Can Write | No |
| Speaks English | Yes |
| Birth State | South Carolina |
| Birth Country | United States |
| Birthplace (normalized) | south carolina |
1920
Charleston, South …
Son, age 12
Charleston, South Carolina · implied b. ~1908 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Johnson |
| Given Name | Isaac |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | Black |
| Age | 12 |
| Marital Status | Single |
| Birthplace | South Carolina |
| Father's Birthplace | South Carolina |
| Mother's Birthplace | South Carolina |
| Can Read | No |
| Can Write | No |
| Speaks English | Yes |
| Birth State | South Carolina |
| Birth Country | United States |
| Birthplace (normalized) | south carolina |
1930
Charleston, South …
Son, age 20
Charleston, South Carolina · implied b. ~1910 — 4 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Johnson |
| Given Name | Isaac |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | Black |
| Age | 20 |
| Marital Status | Single |
| Birthplace | South Carolina |
| Father's Birthplace | South Carolina |
| Mother's Birthplace | South Carolina |
| Occupation | Labor |
| Industry | Acid Mill |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | South Carolina |
| Birth Country | United States |
| Birthplace (normalized) | south carolina |
1940
Charleston-County, South …
Head, age 30
Charleston-County, South Carolina · implied b. ~1910 — 4 household members
| Surname | Johnson |
| Given Name | Isaac |
| Relationship to Head | Head |
| Sex | M |
| Color / Race | Black |
| Age | 30 |
| Marital Status | Married |
| Birthplace | South Carolina |
| 1935 Residence (City) | Charleston City |
| 1935 Residence (County) | Charleston |
| Occupation | Laborer |
| Industry | Fertilizer Plant |
| Class of Worker | PW |
| Hours Worked | 55 |
| Income (1939) | 700 |
| Highest Grade | No 4 |
| 1935 Residence | Same place |
| Birth State | South Carolina |
| Birth Country | United States |
| Birthplace (normalized) | south carolina |
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 Isaac Johnson across 4 US Census years (1910, 1920, 1930 and 1940) in 3 locations, using XGBoost record linkage. Identified parents: father Isaac Johnson (~0.92 confidence) and father James Johnson (~0.92 confidence) and father Isaac Johnson (~0.92 confidence) and mother Hester Johnson (~0.92 confidence) and mother Lizzie Johnson (~0.92 confidence) and mother Irene Johnson (~0.92 confidence). The pedigree spans 1 generation with 6 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Father
Isaac Johnson
b. ~1885
Source father
● Household
· direct · ~0.92
Father
James Johnson
b. ~1885
Source father
● Household
· direct · ~0.92
Father
Isaac Johnson
b. ~1888
Source father
● Household
· direct · ~0.92
Mother
Hester Johnson
b. ~1890
Source mother
● Household
· direct · ~0.92
Mother
Lizzie Johnson
b. ~1890
Source mother
● Household
· direct · ~0.92
Mother
Irene Johnson
b. ~1892
Source mother
● Household
· direct · ~0.92
This person
Anchor record
Isaac Johnson
Head · 1940 · age 30 · b. ~1910 · South Carolina
★ 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 — Charleston-County, South Carolina
Open full size
1940 US Federal Census — Charleston-County, South Carolina
Page Contents
40 people indexed on this census page (nara:1940:m-t0627-03794-00185)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 41 | Jesse C. Matthews | 38 | Head | Engineer | South Carolina |
| 42 | Hallie Matthews | 29 | Wife | — | South Carolina |
| 43 | Juan G. Matthews | 4 | Daughter | — | South Carolina |
| 44 | Helen H. Turner | 62 | Head | — | South Carolina |
| 45 | William S. Turner | 40 | Son | Pipefitter | South Carolina |
| 46 | Laura Matthews | 68 | Head | — | South Carolina |
| 47 | Jack Matthews | 19 | Son | Store Clerk | South Carolina |
| 48 | Frances Matthews | 14 | Daughter | — | South Carolina |
| 49 | William Caffie | 24 | Head | Laborer | South Carolina |
| 50 | Mary Caffie | 27 | Wife | — | South Carolina |
| 51 | Josephine Caffie | 4 | Daughter | — | South Carolina |
| 52 | Carrie Caffie | 1 | Daughter | — | South Carolina |
| 53 | Henry Scott | 31 | Head | Laborer | South Carolina |
| 54 | Sadie Scott | 28 | Wife | — | South Carolina |
| 55 | Henry Scott | 5 | Son | — | South Carolina |
| 56 | Irene Scott | 4 | Daughter | — | South Carolina |
| 57 | Viola Scott | 3 | Daughter | — | South Carolina |
| 58 | James Simmons | 29 | Head | Laborer | South Carolina |
| 59 | Mabel Simmons | 26 | Wife | — | South Carolina |
| 60 | Edward Simmons | 3 | Son | — | South Carolina |
| 61 | John Simmons | 1 | Son | — | South Carolina |
| 62 | Henry Smalls | 44 | Head | Delivery Boy | South Carolina |
| 63 | Jackie Smalls | 20 | Wife | — | South Carolina |
| 64 | Daisy Smalls | 1 | Daughter | — | South Carolina |
| 65 | Henry Williams | 34 | Head | Laborer | South Carolina |
| 66 | Janie Williams | 30 | Wife | — | South Carolina |
| 67 | Jessie Williams | 5 | Daughter | — | South Carolina |
| 68 | John Williams | 3 | Son | — | South Carolina |
| 69 | Julius Williams | 2 | Son | — | South Carolina |
| 70 | Isaac Johnson THIS PERSON | 30 | Head | Laborer | South Carolina |
| 71 | Sarah Johnson | 27 | Wife | — | South Carolina |
| 72 | Willie Johnson | 5 | Son | — | South Carolina |
| 73 | Joe Johnson | 3 | Son | — | South Carolina |
| 74 | John Merritt | 29 | Head | Carpenter | South Carolina |
| 75 | Rebecca Merritt | 29 | Wife | — | South Carolina |
| 76 | Maybell Merritt | 4 | Daughter | — | South Carolina |
| 77 | Irene Merritt | 1 | Daughter | — | South Carolina |
| 78 | Andrew Jordan | 23 | Head | Delivery Boy | South Carolina |
| 79 | Carrie Jordan | 20 | Wife | — | South Carolina |
| 80 | Alex Jordan | 1 | Son | — | South Carolina |
Pedigree Summary
Isaac
Gen 1 · 6 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)