He was sent as a representative and arbitrator by the Jerusalem community to Russia in an important European rabbinic dispute.
[citation needed] The outbreak of World War I prevented his return to Palestine and in 1915 he went to Boston to collect money for charity (tzedakah).
He attracted a small group of followers but soon left Boston for New York.
[3] In 1939 Rabbi Pinchas Horowitz relocated the congregation to the Williamsburg section of Brooklyn, remaining there until his death on November 28, 1941.
[3] Horowitz's successors were his sons, rabbis Moshe Horowitz, the Bostoner Rebbe of New York, and Levi Yitzchok Horowitz, the Bostoner Rebbe of Boston and Har Nof, Jerusalem.