His first Hebrew work Emek ha-Arazim, a historical novel inspired by Grace Aguilar's Vale of Cedars, was published in Warsaw in 1875, which enjoyed great popularity.

Friedberg was an early member of the proto-Zionist Ḥibbat Zion movement, which he joined after the pogroms of 1881, and began to campaign for Jewish settlement in the Land of Israel in the pages of Ha-Melitz.

[5] Friedberg's Rab le-Hoshia (Warsaw, 1886), which was first published in Ha-Tzfirah, is a translation of Asher Sammter [wikidata]'s Rabbi von Liegnitz.

Zikronot le-bet David (Warsaw, 1893–97), a history of the Jewish people, was published in four parts between 1893 and 1897, the first two adapted from Hermann Reckendorf [he]'s Geheimnisse der Juden.

[3] Sefer ha-Torah veha-Ḥayyim, a three-volume translation of Moritz Güdemann's Geschichte des Erziehungswesen, with notes, additions, and a preface, was published in Warsaw between 1896 and 1899.