I'd always wondered about the western European influence in the nascent movement. Apparently, while displaced with her family in Vienna during WWI she heard a sermon based on the writings of Rabbi Samson Raphael Hirsch, whom she was captivated by, and whose writings formed the basis for much of her lessons. She staffed her school with western educators, such as Rebbetzin Dr. Judith (Rosenbaum) Grunfeld.
(On the flip side, one of the premier and most influential educators on the American scene was a Hungarian born rabbi named Rabbi Shraga Feivel Mendlowitz, who spearheaded the day school movement, taught in a Lithuanian yeshiva - Torah V'Daas of Brooklyn - and was learned, and taught Chassidic thought to many Americans. The major influences in education as we know it are something of a cholent pot of the best kind ;-)