R' Gavriel Ze'ev Wolf (Velvel) Margolis z"l was born in Vilna on 27 Cheshvan 5608/1847, the son of the scholar and kabbalist R' Yechiel Yitzchak Margolis. From age 14 to age 17, young Velvel studied under R' Yaakov Brit (1797-1883), one of the teachers of the Chafetz Chaim. In the letter of semichah/ordination that R' Brit gave R' Velvel in 1869, the teacher wrote: "He became great and greater still, not like the greatness of students who succeed in their studies after five years - he, in a short time, volume his friends; they chased him but could not catch him, because his belly was filled with Talmud and halachah." In 1864, the young R' Margolis married the daughter of another teacher of the Chafetz Chaim, the famed tzaddik R' Nachumke of Horodna (Grodno).
Beginning in 1876, R' Margolis served as rabbi in several Lithuanian towns. In 1880, after the death of his father-in-law, he settled in Grodno where he taught for 27 years. In 1907, he was brought to Boston, Massachusetts as its Chief Rabbi. In 1912, R' Margolis moved to 203 East Broadway on Manhattan's Lower East Side as rabbi of the United Hebrew Community of N.Y., Adas Yisrael of New York Congregation in the same building. A Bais Din, under his leadership, flourished there until his demise. He was also the leading proponent of irrefutable kashus standards in N.Y.C. He died on 11 Elul 5695/1935. His demise and funeral made headlines in most New York major newspapers.
R' Margolis' five volume Torah commentary Torat Gavriel was published in the 1920's together with his commentaries on the haftarot and the five megillot. All the books are now collector’s items much cherished by their owners. In the foreword to Torat Gavriel, R' Margolis mentions his plans to write a book on the state of American Jewry. (Sources: Torat Gavriel, Foreword; Otzar Ha'rabbanim No. 4305)