German-born American printer and Pietist leader of the Pennsylvania Germans.

Sower migrated with his wife and son Christopher to Germantown, Pa., in 1724. He was an artisan skilled in many crafts, was profoundly religious, and found his true career in 1738 as the first successful printer to the numerous Germans in colonial America. The output from his large and prolific press included a newspaper, Der Hoch-Deutsch Pensylvanische Geschicht-Schreiber, retitled Pensylvanische Berichte in 1748; an almanac, Der Hoch-Deutsch Americanische Calender; and more than 150 other imprints, mostly religious and in German, from broadsides to the first European-language colonial Bible (1743).

Sower's Pietism was evident in all his activities. He urged the politically apathetic Pennsylvania Germans to go to the polls to maintain pacifist and oath-denying Quakers in power. He worked for legislation to stop mistreatment of immigrants, dissemination of medical knowledge, building of hospitals, and maintenance of the German culture. He opposed defense measures, compulsory Anglicization of Germans, slavery, higher education, and traditional religions, with their forms, sectarianism, and professional clergy. Both his press and his principles were continued by his son Christopher (1721–84) after his death.