Following an earthquake in Safed in 1864, the family (which included Chaim's older brother, Rabbi Yitzchok Hirschensohn) moved to Jerusalem.

Like his brother, the young Zionist Chaim Hirschensohn worked with Eliezer Ben-Yehuda to revive spoken Hebrew and helped found the Safah Berurah ("Plain Language") society in Jerusalem.

Returning to Jerusalem, Hirschenson taught Talmud at the Lemel School; established a publishing house; published, together with his wife and brother, a Yiddish paper called Beit Yaakov; assisted running the Abarbanel library (later absorbed in the National Library of Israel); and established a B’nai B’rith office in Jerusalem.

"When the Turkish government issued a prohibition against selling property to Jews in Palestine, Hirschensohn’s financial situation deteriorated, and he left the country to secure a stable livelihood.

His grandchildren included Stanford University pediatrician Ruth T. Gross and MIT political scientist Ithiel de Sola Pool.

In order for the family to emigrate to the United States, Benjamin at age 15 was sent ahead by ship to find a synagogue for his father to lead.