3 Marcheshvan Yahrtzeit of the Heiliger Ruziner.
(6-) 7 Marcheshvan This is the day that the last of the pilgrims to the Beis Hamikdash returned home. On this day (and for this reason) Jews in the Holy Land begin asking for rain.
11 Marcheshvan yahrtzeit of ... Misushelach ? Rochel Imeinu Reb Nochum Tchernubiler The "Raza" (Rebbe Rashab's brother).
17 Marcheshvan The day the flood (Mabul) started in year 1656 (since creation).
20 Marcheshvan Birthday of the fifth Lubavitcher Rebbe, ''The Rebbe RASH''AB (Sholom Dovber). He was born in 5621 (1860).