JF
John Frederick — 1930 US Census Record
Linked across censuses1930 United States Federal Census · Baltimore, Maryland
Our Model Tree links this John Frederick across the 1920 and 1930 US Censuses in Baltimore, Maryland (XGBoost, ~Confirmed) — first a son (b.~1913), then head of a 7-person household.
Age 17
b. ~1913
Male
Son
Born: Maryland
Single
1930 Census Record Details
| Census Year | 1930 |
| Location | Baltimore, Maryland |
| Surname | Frederick |
| Given Name | John R. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 17 |
| Marital Status | Single |
| Birthplace | Maryland |
| Father's Birthplace | Maryland |
| Mother's Birthplace | Germany |
| Additional Details | |
| Occupation | Supervisor |
| Industry | Electric Mfg Co |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
| Occupation | Supervisor |
| Township / Ward | District 3 Part |
| Est. Birth Year | ~1913 |
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 1930 census.
| Name | Relation to head | Relative to John | Age | Birth yr |
|---|---|---|---|---|
| Margaret Frederick | Daughter | — | 9 | ~1921 |
| Elizabeth Frederick | Daughter | — | 15 | ~1915 |
| Herman Frederick | Son | — | 11 | ~1919 |
| John Frederick | Son | — | 17 | ~1913 |
| Milton Frederick | Son | — | 6 | ~1924 |
| Herman Frederick | Head | — | 46 | ~1884 |
| Johanna Frederick | Spouse | — | 44 | ~1886 |
Census Appearances
1920
Baltimore, Maryland
Son, age 7
Baltimore, Maryland · implied b. ~1913 — 6 household members
●
Primary link
· ~Confirmed · 2 sources
XGBoost
Household
| Surname | Frederick |
| Given Name | John |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 7 |
| Marital Status | Single |
| Birthplace | Maryland |
| Father's Birthplace | Maryland |
| Mother's Birthplace | East Prussia |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
1930
Baltimore, Maryland
Son, age 17
Baltimore, Maryland · implied b. ~1913 — 7 household members
| Surname | Frederick |
| Given Name | John R. |
| Relationship to Head | Son |
| Sex | M |
| Color / Race | White |
| Age | 17 |
| Marital Status | Single |
| Birthplace | Maryland |
| Father's Birthplace | Maryland |
| Mother's Birthplace | Germany |
| Occupation | Supervisor |
| Industry | Electric Mfg Co |
| Class of Worker | W |
| Can Read/Write | Yes |
| Birth State | Maryland |
| Birth Country | United States |
| Birthplace (normalized) | maryland |
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 Frederick across 2 US Census years (1920 and 1930) in Baltimore, Maryland, using XGBoost record linkage.
Show:
This person
Anchor record
John Frederick
Son · 1930 · age 17 · b. ~1913 · Maryland
★ You are viewing this record
Sibling
Milton Frederick
Sibling · 1930 · age 6
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Elizabeth Frederick
Sibling · 1930 · age 15
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Herman Frederick
Sibling · 1930 · age 11
Source co-child of head (derived)
● Co-child · derived · ~0.88
Sibling
Margaret Frederick
Sibling · 1930 · age 9
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 — Baltimore, Maryland
Open full size
1930 US Federal Census — Baltimore, Maryland
Page Contents
50 people indexed on this census page (ia:1930:15thcensus846unit:0085)
| Line | Name | Age | Relation | Occupation | Birthplace |
|---|---|---|---|---|---|
| 1 | Andrew J. Ii Young | 40 | Head | Broker | Maryland |
| 2 | Elizabeth D. Young | 38 | Wife | — | Maryland |
| 3 | Andrew J. Iii Young | 13 | Son | — | Maryland |
| 4 | Elizabeth W. Young | 7 | Daughter | — | Maryland |
| 5 | Kenneth H. Young | 6 | Son | — | Maryland |
| 6 | Wesley Hart | 38 | Head | Chauffeur | Maryland |
| 7 | Martha S. Hart | 36 | Wife | — | Maryland |
| 8 | Mary S. Martindale | 50 | Head | — | Maryland |
| 9 | Murray N. Martindale | 23 | Daughter | Typist | Maryland |
| 10 | Elizabeth V. Martindale | 21 | Daughter | File Clerk | Maryland |
| 11 | Conley V. Martindale | 20 | Son | Salesman | Maryland |
| 12 | Joseph Neal | 40 | Head | Laborer | Maryland |
| 13 | Irene Neal | 30 | Wife | Cook | Maryland |
| 14 | Herman O. Frederick | 46 | Head | Machinist | Maryland |
| 15 | Johanna E. Frederick | 44 | Wife | — | Germany |
| 16 | John R. Frederick THIS PERSON | 17 | Son | Supervisor | Maryland |
| 17 | Elizabeth B. Frederick | 15 | Daughter | Shirt Trimmer | Maryland |
| 18 | Herman Frederick | 11 | Son | — | Maryland |
| 19 | Margaret Frederick | 9 | Daughter | — | Maryland |
| 20 | Milton Frederick | 6 | Son | — | Maryland |
| 21 | John Whites | 50 | Head | Night Watchman | Maryland |
| 22 | Eila L. Whites | 37 | Wife | — | Virginia |
| 23 | John Whites | 6 | Son | — | Maryland |
| 24 | William C. Whites | 2 | Son | — | Maryland |
| 25 | John C. Young | 44 | Head | Chauffeur | Maryland |
| 26 | Clara Young | 38 | Wife | Servant | Maryland |
| 27 | Rosa B. Jackson | 37 | Head | — | Maryland |
| 28 | George W. Jackson | 72 | Brother-in-law | Electrician | Maryland |
| 29 | Mollie Miller | 65 | Aunt | — | Maryland |
| 30 | Charles J. Schwatha | 69 | Father | Night Watchman | Maryland |
| 31 | Frank A. Schwatha | 34 | Brother | Commission Merchant | Maryland |
| 32 | Philip L. Haller | 29 | Head | Baker | New York |
| 33 | Irene H. Haller | 28 | Wife | — | Ohio |
| 34 | Roman Frazier | 35 | Head | Cook | South Carolina |
| 35 | Blanche E. Frazier | 29 | Wife | — | Maryland |
| 36 | Virginia Frazier | 11 | Daughter | — | Maryland |
| 37 | Roman Jr. Frazier | 9 | Son | — | Maryland |
| 38 | John W. Frazier | 8 | Son | — | Maryland |
| 39 | Esther V. Frazier | 7 | Daughter | — | Maryland |
| 40 | Henry W. E. Krumm | 64 | Head | Mechanic | Maryland |
| 41 | Margaret C. Krumm | 64 | Wife | — | Maryland |
| 42 | Henry W. Krumm | 36 | Son | Salesman | Maryland |
| 43 | James C. Souders | 39 | Head | Salesman | South Carolina |
| 44 | Emily C. Souders | 43 | Wife | — | Maryland |
| 45 | Mattie C. Fowler | 17 | Step-daughter | Secretary | Maryland |
| 46 | William S. Brooks | 60 | Head | Builder | Maryland |
| 47 | Mary S. Brooks | 53 | Wife | — | Maryland |
| 48 | Viola L. Brooks | 31 | Daughter | Typist | Maryland |
| 49 | Charles Brooks | 30 | Son | Carpenter | Maryland |
| 50 | Allen E. Brooks | 26 | Son | Carpenter | Maryland |
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)