This is one of the few Hasidic dynasties named after an American city (others are Boston, Cleveland, Milwaukee[broken anchor] and Philadelphia).
The Hasidut was led by Rabbi Avraham Abba's son, Rabbi Mordechai Yissachar Ber Leifer, who died Chol Hamoed Succos 2020, presided over a nucleus of about 100 Pittsburgher families in Ashdod as well as families in Jerusalem, Bnei Brak, Beit Hilkia, New York City and California.
[1] Owing to the small size of the Hasidut, each member had a personal relationship with the Rebbe and Rebbetzin, who spoke English, Hebrew and Yiddish.
A fascinating story in connection with the niggun and the baby at the bris was printed in the English Hamodia newspaper in 2006.
[3] The very popular tune known throughout the Jewish world, including in non-Orthodox synagogues, for "Yismechu HaShamayim" is also a Pittsburger niggun, composed by the first Pittsburgher Rebbe.