Although Philip Schaff was from Germany and originally a minister in the German Reformed Church, he later came to America joined the Presbyterian Church in the USA and served on the faculty of Union Theological Seminary in New York.
And although he was an exponent of Mercersburg Theology, he was also a very able and judicious church historian. A prolific writer, he published the first volume of his History of the Christian Church in 1858. Volumes 2-4, 6 and 7 were also published during his lifetime, and vols. 5, part 1 and 2 were edited and published by his son, David Schley Schaff, posthumously. Three volumes of The Creeds of Christendom were published in 1877. These two sets, in particular, have been republished to the present day, and remain standard works in church history and historical theology.
These, along with other volumes by these two noted church historians, are now available to read at Log College Press.