This Rav seems to have lived in Turicsa or Turi'a Remete in western
Ukraine. He had a son, Rav Aharon sega"l Yacobowitz, whose own son
(Zvi Dov) was circumcized in 1875-76 in Turicsa. Rav Ya'akov also had
a daughter, Leah or Lena Yacobowitz, who, in 1863, married Moshe Lieb
(Morice) Feldman, the Mohel at Velke Berezne (also western Ukraine)
where the Yacobowitz-Feldman couple lived. We are very interested in
finding more about the Yacobowitz family.