What is the name of the national movement of the Jewish people did Samuel Gruber "aka" Mieczyslaw Gruber belong to?
Mieczyslaw Gruber:  As a youth, Gruber belonged to the Zionist organizations Ha-Shomer ha-Tza'ir and He-halutz. Zionism: Zionism (Hebrew: צִיּוֹנוּת‎ "Tsiyyonut" ] after "Zion") is the national movement of the Jewish people that supports the re-establishment of a Jewish homeland in the territory defined as the historic Land of Israel (roughly corresponding to Canaan, the Holy Land, or the region of Palestine).
Zionism