Bronia (Breyndl) Baum (1896–1947) was an Orthodox Jewish writer, activist, and journalist. She was born into a Hasidic family in Tomaszów Mazowiecki, moved to Piotrków Trybunalski in 1918, and then to Łódź. In 1925, she left Poland for the Land of Israel. Among poems and articles that she published in Yiddish papers were “Der Yud,” “Dos Yidishe Togblat,” and “Beys Yankev.” She also wrote in Hebrew—“Bat Israel” and “Baderekh” are two examples—with her Hebrew writing collected in Ketavim le-bat Yisra’el, published in Tel Aviv in 1954. Baum energetically promoted women’s education, an active role for religious Jewish women, and a number of charities. This article analyzes Bronia Baum’s unpublished manuscripts from the years 1912 to 1921. They include a diary in Russian and poems in Polish and Yiddish, and together constitute a unique literary and historical document. Baum’s work is considered from five perspectives: (1) the critical importance of education; (2) the role of World War I in shaping and determining her opinions and worldview, and of antisemitism in developing her Zionist stance; (3) her position on tradition and religion; (4) feminist motifs in her manuscripts, along with her attitude toward men and her relations with women; and (5) her approach toward her own writing, her compulsion to write and its source.