He was named after his maternal grandfather Nisson Lipa Joselowitz, rosh yeshiva in Lazday, Poland, and later the rabbi of Polanka.
Rebbetzin Alpert obtained one of the first transit visas from Chiune Sugihara, and crossed Russia with the family to Japan.
From there they traveled to San Francisco, and finally to the Lower East Side of New York City.
Although Alpert arrived in America at the age of 12 with no knowledge of English, he graduated Washington Irving High School as valedictorian of his class.
He learned at Mesivtha Tifereth Jerusalem, where he became a very close disciple of Rabbi Moshe Feinstein.