Schlatter was educated at the gymnasium of St. Gallen, after which he was tutored in theology, and then proceeded to the University of Leyden and then the University of Helmstedt in Brunswick. He then returned to his tutor for some time before being ordained in 1739. He taught for several years in Holland and then entered the German Reformed ministry. He officiated a few months in Switzerland, and then offered his services as a missionary to the German Reformed emigrants in Philadelphia in 1746, after learning of a request made to the Dutch Reformed Church for ministers by German Reformed clergyman John Phillip Boehm and went to Pennsylvania in that year, arriving on 6 August. He served as pastor of the united churches of Germantown and Philadelphia in 1746-51, organized a synod which met in Philadelphia in 1747, and made extended missionary tours among the German Reformed settlers in Pennsylvania, Maryland, Virginia, New Jersey and New York State.
In 1751, he returned to Europe to report on his work. In Amsterdam, he published (1751) a journal of his experiences and transactions in America, with an account of the Reformed congregations and their dearth of pastors. Of this book, he made a German translation (Frankfort, 1752), and afterward it was rendered into English by Rev. David Thomson, of Amsterdam, and distributed throughout Great Britain. As a result of Schlatter's appeal, £20,000 was raised in England and Holland for the establishment of free schools among the Germans in America. He also secured the assistance of six young preachers, and 700 Bibles.
In March 1752, Schlatter returned to Philadelphia with the money and preachers, and in 1755 withdrew from his pastoral activities to become superintendent of the establishment of the schools among the Germans under the auspices of the Society for the Propagation of the Knowledge of God among the Germans, a group of people from London, of whom William Smith was secretary. The schools were unpopular with the Germans, and in 1757 Schlatter resigned his superintendency. He then accepted an offer by Lord Loudoun to become chaplain of the Royal American regiment, which he accompanied on an expedition to Louisburg. He remained with the army until 1759, and then preached at Chestnut Hill and surrounding places. In 1764 he was a chaplain to the 2nd Pennsylvania Battalion under Henry Bouquet on a mission against the Indians.
In 1777, while still attached to the royal army, he refused to obey orders on account of sympathy with the colonial cause. He was imprisoned, and his house was plundered.
- This article incorporates text from a publication now in the public domain: Rines, George Edwin, ed. (1920). "Schlatter, Michael". Encyclopedia Americana. This publication in turn cites:
- Harbaugh, Henry, Life of Rev. Michael Schlatter (1857)
- This article incorporates text from a publication now in the public domain: Wilson, James Grant; Fiske, John, eds. (1900). "Schlatter, Michael". Appletons' Cyclopædia of American Biography. New York: D. Appleton. This publication in turn cites:
- Life by Rev. Henry Harbaugh (Philadelphia, 1857)
- J. I. Good, History of the Reformed Church in the United States, 1725-1792, 1899
- M. Pritzker-Ehrlich, Michael Schlatter von St. Gallen (1716-1790), 1981
- Harbaugh, Henry (1857). The life of Rev. Michael Schlatter; with a full account of his travels and labors among the Germans in Pennsylvania, New Jersey, Maryland and Virginia; including his services as chaplain in the French and Indian War, and in the war of the revolution, 1716 to 1790. Philadelphia: Lindsay and Blakiston.
- "Schlatter, Michael". New International Encyclopedia. 1905.