JD
John Duffy — 1930 US Census Record
Model Tree available1930 United States Federal Census · Charleston, South Carolina
Our Model Tree links this John Duffy across the 1910, 1920 and 1930 US Censuses in Charleston, South Carolina (XGBoost, ~Confirmed), with identified parents Anna & John — first a son (b.~1903), then head of a 6-person household.
Age 27
b. ~1903
Male
Son
Born: South Carolina
Single
1930 Census Record Details
| Census Year | 1930 |
| Location | Charleston, South Carolina |
| Surname | Duffy |
| Given Name | John J. Jr. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Single |
| Birthplace | South Carolina |
| Father's Birthplace | South Carolina |
| Mother's Birthplace | South Carolina |
| Additional Details | |
| Occupation | Pharmacist |
| Industry | Drug Store |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | South Carolina |
| Birth Country | United States |
| Birthplace (normalized) | south carolina |
| Occupation | Pharmacist |
| Township / Ward | Charleston City |
| Est. Birth Year | ~1903 |
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.
6 people recorded at the same address in the 1930 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Katherine Duffy | Daughter | — | 19 | ~1911 |
| John Duffy | Head | — | 60 | ~1870 |
| Gustavus Duffy | Son | — | 21 | ~1909 |
| John Duffy | Son | — | 27 | ~1903 |
| Andrew Duffy | Son | — | 31 | ~1899 |
| Annie Duffy | Spouse | — | 57 | ~1873 |
Census Appearances
1910
Charleston, South …
Son, age 7
Charleston, South Carolina · implied b. ~1903 — 9 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 7 |
| Marital Status | Single |
| Birthplace | South Carolina |
| Father's Birthplace | South Carolina |
| Mother's Birthplace | South Carolina |
| Birth State | South Carolina |
| Birth Country | United States |
| Birthplace (normalized) | south carolina |
1920
Charleston, South …
Son, age 17
Charleston, South Carolina · implied b. ~1903 — 10 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Duffy |
| Given Name | John J. Jr. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 17 |
| Marital Status | Single |
| Birthplace | South Carolina |
| Father's Birthplace | South Carolina |
| Mother's Birthplace | South Carolina |
| Occupation | Asst. Clerk |
| Industry | Insurance |
| Class of Worker | W |
| Can Read | Yes |
| Can Write | Yes |
| Speaks English | Yes |
| Birth State | South Carolina |
| Birth Country | United States |
| Birthplace (normalized) | south carolina |
1930
Charleston, South …
Son, age 27
Charleston, South Carolina · implied b. ~1903 — 6 household members
| Surname | Duffy |
| Given Name | John J. Jr. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 27 |
| Marital Status | Single |
| Birthplace | South Carolina |
| Father's Birthplace | South Carolina |
| Mother's Birthplace | South Carolina |
| Occupation | Pharmacist |
| Industry | Drug Store |
| Class of Worker | W |
| Can Read/Write | Yes |
| 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 John Duffy across 3 US Census years (1910, 1920 and 1930) in Charleston, South Carolina, using XGBoost record linkage. Identified parents: mother Anna Duffy (~0.92 confidence) and father John Duffy (~0.92 confidence) and father John Duffy (~0.92 confidence) and father John Duffy (~0.92 confidence) and mother Annie Duffy (~0.92 confidence). The pedigree spans 1 generation with 5 identified ancestors.
Show:
Gen 1
Parents
confidence ≈ 0.92
Mother
Anna Duffy
b. ~1869
Source mother
● Household
· direct · ~0.92
Father
John Duffy
b. ~1870
Source father
● Household
· direct · ~0.92
Father
John Duffy
b. ~1870
Source father
● Household
· direct · ~0.92
Father
John Duffy
b. ~1871
Source father
● Household
· direct · ~0.92
Mother
Annie Duffy
b. ~1874
Source mother
● Household
· direct · ~0.92
This person
Anchor record
John Duffy
Son · 1930 · age 27 · b. ~1903 · South Carolina
★ You are viewing this record
Sibling
Andrew Duffy
Sibling · 1930 · age 31
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Gustavus Duffy
Sibling · 1930 · age 21
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Katherine Duffy
Sibling · 1930 · age 19
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
1930 US Federal Census — Charleston, South Carolina
Open full size
1930 US Federal Census — Charleston, South Carolina
Page Contents
50 people indexed on this census page (ia:1930:15thcensus2189unit:0612)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Robert Frasier | 16 | Son | Porter | South Carolina |
| 2 | Annabel Frasier | 10 | Daughter | — | South Carolina |
| 3 | Herman Frasier | 7 | Son | — | South Carolina |
| 4 | Ben Frasier | 5 | Son | — | South Carolina |
| 5 | Ella Frasier | 2 | Daughter | — | South Carolina |
| 6 | Oscar Frasier | 0 | Son | — | South Carolina |
| 7 | Ben Smith | 37 | Lodger | Butler | South Carolina |
| 8 | R. B. Hare | 25 | Head | Interne | South Carolina |
| 9 | Mary Hare | 22 | Wife | — | North Carolina |
| 10 | Herbert Bailey | 38 | Head | Interne | South Carolina |
| 11 | Thelma Bailey | 24 | Wife | — | South Carolina |
| 12 | Betty Bailey | 5 | Daughter | — | South Carolina |
| 13 | Martin Danielson | 41 | Head | Engineer | Norway |
| 14 | Harriet Danielson | 27 | Wife | — | Georgia |
| 15 | Jason Sr. Walker | 80 | Head | Retired | Kentucky |
| 16 | Marguerite Walker | 41 | Daughter | Technician | Kansas |
| 17 | Thomas A. Bray | 44 | Head | Clerk | Georgia |
| 18 | Mamie Bray | 33 | Wife | — | South Carolina |
| 19 | Thomas Jr. Bray | 6 | Son | — | South Carolina |
| 20 | Doris Bray | 5 | Daughter | — | South Carolina |
| 21 | Walter Bray | 0 | Son | — | South Carolina |
| 22 | Harold Wolff | 16 | Nephew | Salesman | South Carolina |
| 23 | Eugenia Wolff | 66 | Mother | — | South Carolina |
| 24 | Milton Hagan | 28 | Head | Switchman | South Carolina |
| 25 | Mamie Hagan | 27 | Wife | Teacher | South Carolina |
| 26 | Helen Hagan | 4 | Daughter | — | South Carolina |
| 27 | Elizabeth Hagan | 0 | Daughter | — | South Carolina |
| 28 | S. Ranson Lewis | 53 | Head | Bookkeeper | Pennsylvania |
| 29 | Mabel S. Lewis | 45 | Wife | — | Pennsylvania |
| 30 | Ida C. Lewis | 22 | Daughter | — | Pennsylvania |
| 31 | Mabel Lewis | 16 | Daughter | — | Indiana |
| 32 | John J. Duffy | 60 | Head | Plumber | South Carolina |
| 33 | Annie Duffy | 57 | Wife | — | South Carolina |
| 34 | Andrew Duffy | 31 | Son | Fireman | Georgia |
| 35 | John J. Jr. Duffy THIS PERSON | 27 | Son | Pharmacist | South Carolina |
| 36 | Gustavus Duffy | 21 | Son | Salesman | South Carolina |
| 37 | Katherine Duffy | 19 | Daughter | — | South Carolina |
| 38 | J. Henry Wittschen | 22 | Head | Clerk | South Carolina |
| 39 | Dolores Wittschen | 17 | Wife | Stenographer | South Carolina |
| 40 | R. Earl Fischer | 31 | Head | Automobile | South Carolina |
| 41 | Alice Fischer | 30 | Wife | — | South Carolina |
| 42 | W. Alice Fischer | 3 | Daughter | — | South Carolina |
| 43 | Barbara Fischer | 1 | Daughter | — | South Carolina |
| 44 | John T. Weston | 70 | Head | Bookkeeper | South Carolina |
| 45 | Paige Weston | 70 | Wife | — | South Carolina |
| 46 | William S. Weston | 33 | Son | Teller | South Carolina |
| 47 | Charlotte Weston | 33 | Daughter-in-law | — | South Carolina |
| 48 | Helen Weston | 2 | Granddaughter | — | South Carolina |
| 49 | Mildred W. Lewis | 39 | Daughter | Teacher | South Carolina |
| 50 | Paul P. King | 38 | Head | Chief Engineer | South Carolina |
Related Census Records
Pedigree Summary
John + 3 siblings
Gen 1 · 5 parents
~0.92
Max depth 4 (1900–1950 window)
About This Record & Model Tree
This record was independently indexed by YourRoots from the 1930 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)