The school band of the Natanson Professional School pose with their instruments in front of the school on 26 Grzybowska Street. World War I and its disruptive aftermath threatened the religious, educational, and cultural institutions that had made Poland one of the most important centers of Jewish scholarship, learning and culture. In the interwar period, the American Jewish Joint Distribution Committee (“the Joint”), a humanitarian organization, played a vital role in restoring and helping to support Jewish schools and institutions, working in partnership with the entire spectrum of Jewish groups and ideologies: Hasidic groups, Zionists, Bundists, Yiddishists, and representatives of mainstream Orthodoxy.