During World War I, the Russian military authorities decided that Jews could not live close to the Kovno fortress, and they were banished from Slabodka by force.

[7] In 1933, with his father-in-law's encouragement, Ruderman moved to Baltimore, where he was immediately offered a rabbinical post at Tiferes Yisroel Shul.

He began with six students and named the newly formed yeshiva Ner Yisroel (after Rabbi Yisrael Lipkin Salanter,[8] the founder of the mussar movement).

Rabbi Schwab taught the first-year shiur (class) in Ner Israel for several years, until he moved to Washington Heights.

When Ruderman grew old, he became legally blind but could still read by holding a book within inches of his eyes that wore very thick glasses.

Ruderman led the yeshiva for 54 years until his death when Rabbi Shmuel Yaakov Weinberg, his son in law, took over.

[9] Ruderman was rosh yeshiva, while his brother-in-law, Rabbi Naftoli (Herman) Neuberger took care of the financial side.