Johannes Sybrens Zwart, born circa 1799, milker, died before June 10, 1880, aged at most 81 years.

Johannes was married to
Ruttje Jacobs van der Velde, born circa 1816 (?), died before June 10, 1880, aged at most 64 years.

• 1 : Grietje Johannes Zwart, born in Wartena on May 29, 1839, died after July 31, 1915, aged at least 76 years.
  Grietje was married in Idaarderadeel on June 10, 1880, at the age of 41 to Wybe Ottes Feenstra (aged 38 years), born in Warga on September 1, 1841, son of Otte Wybes Feenstra (bargeman, worker, bargeman and worker) and Johanna Oepkes Bouwma, journeyman baker, died in Wartena on July 31, 1915, aged 73 years.