Shiurim in this topic
The Rebbe's discussion of the halachic questions involved in establishing an eruv, centered on the proposed eruv in Manhattan: the city's boundaries, earlier responsa on the question, and specific points raised in correspondence with Rabbi Yosef David Moskowitz (IK 2786, 2936).
See also: Shabbos and holidays – Keeping Shabbos; Halachah and custom – Who decides halachah, and the Rebbe's halachic responses.