Shmuel Elazar Halperin was a young avrech engaged in Torah education and outreach, to whom the Rebbe wrote in 5717–5718 (1957–58). No reliable published biography is available; the summary below is drawn from the letters themselves.
The Rebbe's six letters to him encourage his work in chinuch and outreach (IK 4907) and give guidance about his role at the Torah Emes yeshiva and inspiring its students (IK 5084). The Rebbe writes on using the summer for learning while maintaining connections (IK 5484), on building a chassidic home and the proper review of maamarim (IK 5726), on growth in spreading the wellsprings and preparing for Yud-Tes Kislev (IK 5872), and on harnessing one's inner strength in Torah education, in light of the Torah's unique power (IK 6320).
See also: Education – Being a teacher; Jewish outreach – Spreading Chassidus.