The Chabad youth organization (Tzach) in Montreal. The Rebbe's letters to its executive date from roughly 1957–1961. See also Tomchei Temimim, Montreal.
Chassidus in the community. The Rebbe urged increasing participation in the repetition of Chassidus on Shabbos by both yeshivah students and married men (IK 4160).
Camps and events. He encouraged ongoing dedication to the growth of Camp Gan Yisrael, stressing its profound spiritual impact (IK 6308), sharing the camp's inspiration afterward (IK 5638), and taught that effort invested in camps and holiday events yields lasting results (IK 5917).
Working together. Cooperation between community organizations brings greater impact when establishing new projects (IK 5495), and educational efforts are most effective when acted on while the inspiration is fresh (IK 5781).
Sources: the Rebbe's letters cited above.