He was born in the hamlet of Kalushkove, Lithuania, in 1891. Shortly afterwards his family moved to the village of Dolhinov where he grew up. He studied in Minsk and then for 21 years in Slabodka yeshiva under Rabbi Nosson Tzvi Finkel. It was there that he met his lifelong friend Rabbi Aharon Kotler, who later founded the Lakewood yeshiva. His younger cousin, Rabbi Yaakov Yitzchak Ruderman, also grew up in Dolhinov. Kamenetsky was appointed rabbi of Tzitavyan in 1926 and moved to North America in 1937, where he initially took rabbinical positions in Seattle and then Toronto. From 1948 to 1968 he headed Mesivta Torah Vodaath in Brooklyn, New York. After leaving the yeshiva he moved to Monsey, New York, where he focused on publishing his books. Along with Rabbi Moshe Feinstein, Reb Yaakov led American Jewry in issues of halachic and spiritual guidance until 1986, when both men died. He was renowned as "Chakima D'Yehudai", the wise man of the Jews. Aside from his extensive Torah scholarship, he was known for his ever-present warm smile and his expertise in Hebrew grammar. He was an advocate for English-language sefarim, even commenting that quality English-language sefarim will be used by Jews in the Messianic era as, like Yiddish in its time, "today English has become a language of Torah."
Family
Kamenetsky's first wife was Itta Ettil Kamenetsky, who died on July 9, 1954. In 1958, Kamenetsky married Chana Urman of Toronto. The mesader kidushin for Rabbi Kamenetsky's marriage to Rebbetzin Chana Kamenetsky was his close friend and colleague, Rabbi Zelik Epstein. Rebbetzin Chana Kamenetsky died shortly after her husband in 1986. Kamenetsky's son, Rabbi Shmuel Kamenetsky heads the Talmudical Yeshiva of Philadelphia, chairs the Moetzes Gedolei HaTorah. His other sons are: Rabbis Binyamin, founder of the Yeshiva of South Shore in Long Island, NY, Nathan, vice Rosh yeshiva at Yeshivas Itri, and author of Making of a Godol on his father, and Avraham. His oldest daughter, Malka, was married to Rabbi Yisrael Shurin. A second daughter, Rivka, was married to Rabbi Hirsch Diskind]. Dozens of his descendants serve in key leadership positions across North America in other countries. They include: Rabbis Mordechai Kamenetzky, Dean of the Yeshiva of South Shore, Shalom Kamenetsky, Rosh Yeshivas Philadelphia, Avraham Kamenetsky, R"M in Yeshivas Beis Yisrael in Jerusalem, Yosef Kamenetsky, Rosh Kollel in Moscow, Zvi Kamenetzky, Dean of the Dwek Ohr HaEmet Sephardic Academy of Toronto, and Yitzchak Shurin, Dean of Midreshet Rachel-Shappell's. His grandson Dov Shurin is a singer-songwriter and musician.
Works
Emes leYaakov al HaShas – a five-volume work with insightful commentary on the Talmud.
Emes leYaakov al Shulchan Aruch – a volume with commentary and rulings on Shulchan Aruch, The Jewish Code of Law
Emes leYaakov – a commentary on Chumash, which includes grammatical observations on the Hebrew of the Bible.
Kamenetsky also left many manuscripts that are being converted into book form by various descendants.
